Equine health encompasses the study and management of diseases, disorders, and overall well-being of horses. It involves understanding various physiological systems, preventive care, and treatment strategies to maintain optimal health in equine populations. Common areas of focus include nutrition, infectious diseases, orthopedic conditions, and reproductive health. Research in equine health aims to advance knowledge on diagnostic methods, therapeutic interventions, and management practices that improve horse welfare and performance. This page collects peer-reviewed research studies and scholarly articles that explore the diverse aspects of equine health, offering insights into current findings and advancements in the field.
Santschi EM, Juzwiak JS, Slone DE.Three monorchid colts were admitted for castration as cryptorchids. Two colts each had one normal descended testis, and the third colt had a small testis in the abdomen. Monorchidism was diagnosed at surgery by locating an incomplete epididymis without a testis. After the incomplete epididymis and other testis were removed, the absence of testicular tissue was confirmed by results of a human chorionic gonadotropin response test.
Reimer JM, Reef VB, Spencer PA.The medical records of 83 horses with pleuropneumonia and/or pulmonary abscessation, in which thoracic sonography was used, were reviewed. The sonograms of these horses were reviewed retrospectively for free gas echoes within pleural or abscess fluid. Anaerobic infection was confirmed in 27 horses, and gas echoes were observed in 21 horses. There was a significant (P less than 0.001) correlation between the observation of gas echoes and anaerobic infection in horses with pleuropneumonia and/or pulmonary abscessation. A foul odor to the breath or pleural fluid was significantly (P less than 0.0...
Held JP, Prater P, Toal RL, Blackford JT, McCracken M.A 7-year-old stallion with a history of abdominal pain after it fell was examined and found to have a swelling of the right testis and epididymis. Semen evaluation revealed an increase in secondary sperm abnormalities. The stallion was unilaterally castrated. The histologic diagnosis was sperm granuloma, with no evidence of infection. Periductal fibrosis was observed and appeared to have developed before the trauma occurred. The changes seen could be compatible with chronic blockade of efferent ductules, resulting in extravasation of spermatozoa.
Spurlock SL, Spurlock GH, Wise M.Keratoconjunctivitis sicca developed in a mare with fracture of the stylohyoid bone. Treatment was directed at preserving the health of the globe while local inflammation at the fracture site was resolved.
Owen RA, Jagger DW, Quan-Taylor R.A caecocaecal intussusception in a pony and a caecocolic intussusception in a horse, both infected with Anoplocephala perfoliata, are described and the relevance of tapeworms in such intestinal disease of horses is reviewed.
Saudek V, Atkinson RA, Williams RJ, Ramponi G.It has been proposed that combination of intraresidue, sequential and longer range nuclear Overhauser enhancements occurring in 1H nuclear magnetic resonance spectra of protein chains folded in a helix show a regular characteristic pattern. As a test case the spectra of horse muscle acylphosphatase were searched for this pattern together with other typical signs of a helical conformation (i.e. chemical shift, coupling constants and slow 2H-H exchange). Two amino acid sequences complying with these requirements were found. Just a few amino acid spin system assignments were then sufficient to lo...
Lombardo D, Chapus C, Bourne Y, Cambillau C.Horse (Equus caballus) pancreatic lipase (EC 3.1.1.3) has been crystallized using the hanging drop method of vapour diffusion at 20 degrees C. The best crystals were grown from an 8 mg/ml solution in 10 to 20% (w/v) polyethylene glycol 8000, 10 mM-MgCl2, 0.1 M-NaCl, 0.1 M-Mes buffer (pH 5.6). They reach dimensions of 0.8 mm x 0.4 mm x 0.6 mm. X-ray examination of the lipase crystals shows that they are orthorombic with a space group P2(1)2(1)2(1). Their cell dimensions are a = 79.8 A, b = 97.2 A c = 145.3 A. Two molecules per asymmetric unit give a Vm value of 2.82 A3/dalton (56% water content...
Saudek V, Williams RJ, Ramponi G.The solution structure of acylphosphatase determined by proton nuclear magnetic resonance spectroscopy is described. The results allow us to discuss the fold of the protein (101 amino acids), to correlate the exposure and the mobility of the backbone with the antigenicity, and to locate the active site.
Gasthuys F, Vandamme R, De Moor A, De Meurichy W.A commercial neuroleptanalgesic acepromazine-etorphine combination administered intramuscularly to four horses produced a severe tachycardia and an increase in muscular tone, together with hypoxaemia, hypercapnia, metabolic acidosis associated with an increase in the packed cell volume and hyperglycaemia. No electrolyte changes were found. After reversal of the action of etorphine with diprenorphine, there was a prolonged decrease in the calcium and phosphorus serum concentrations and decreases in the packed cell volume and the total protein serum concentration. In a second experiment on the s...
Jenkinson DM, Loney C, Elder HY, Montgomery I, Mason DK.Histological studies of the sweat glands of anhidrotic horses in the Hong Kong summer and under conditions of reduced thermal stress, both natural and controlled, were undertaken to determine if glandular regeneration occurs. Clinical data were collected for comparison with the histological results in each instance. Horses were assigned to one of three categories on the basis of the resulting change in the number of thin glandular profiles in a cooler environment. Group 1, which was classed as normal, had a low initial value, which was maintained. Group 2, typical of mild and moderately affect...
Pedersen NC.Lentiviruses are associated with persistent infection and chronic
disease in three major species of livestock—horses, sheep, and goats.
Another lentivirus named bovine immunodeficiency virus (BIV) recently has been described (Gonda et al., 1987). It is a Visna-like virus that was originally isolated over a decade ago from cattle with
persistent lymphocytosis, lymphadenopathy, weakness, emaciation,
and central nervous system (CNS) lesions (Van der Maaten et al,
1972). There is very little information on the epidemiology, clinical
manifestations, or importance of bovine lentivirus infect...
Meijer AE, van den Hoven R, Wensing T, Breukink HJ.In this communication, the results of an enzyme histochemical study on m. gluteus medius of horses, sensitive to exertional myopathy, during attacks of rhabdomyolysis are presented. The activity and location of about 25 enzymes were examined. In the present report, the early metabolic changes are discussed. Within 6 min after an attack, some large rounded fibres (approximately 2%) were seen, which showed an intense red staining in the haematoxylin and eosin sections. These hypercontracted fibres showed an increase in activity of mitochondrial adenosine triphosphatase, indicating the presence o...
Dos-Santos MC, Yamaguchi IK, Caricatti CP, Higashi HG, Dias-da-Silva W.Equines (2 horses and 2 donkeys) immunized with whole Crotalus durissus terrificus venom or its phospholipase A2 component either presented an increased survival time determined 3 days after challenge or were totally resistant to a challenging lethal dose of 200 mg crude venom 270 days after the initial immunization or 90 days after the last booster injection. The resistance was demonstrable on the basis of a good correlation with antibody titers determined by the ELISA method but not with the flocculation and neutralization assays. Since phospholipase A2 is essentially nontoxic, it can be use...
Vaughn DM, Smyth GB.The serotonin metabolite, 5-hydroxyindoleacetic acid (5-HIAA) and the dopamine metabolite, homovanillic acid (HVA) in the cerebrospinal fluid (CSF) of seven clinically normal horses were evaluated with reverse phase high pressure liquid chromatography and electrochemical detection. Comparisons of the neurotransmitter metabolite concentrations were made on CSF collected simultaneously from the atlanto-occipital and lumbosacral regions. There were significantly higher amounts of 5-HIAA and HVA in atlanto-occipital CSF than in lumbosacral CSF. Mean 5-HIAA concentrations in atlanto-occipital and l...
Art T, Lekeux P.This paper attempts to evaluate the changes in the mechanical work of breathing induced by the increase of ventilation in ponies exercising on a treadmill. Airflow, tidal volume (VT) and oesophageal pressure were simultaneously recorded in eight ponies (four to six years old and weighing 258 +/- 11 kg) before, during and after standardised exercise. Respiratory frequency, VT and minute volume (Ve) for each phase of the experimental protocol were calculated from the collected data. The pressure-volume diagrams were traced and the work per cycle (Wrm) was estimated by measuring the area enclosed...
Ibarra-Rubio ME, Pena JC, Pedraza-Chaverri J.1. Serum angiotensin-converting enzyme activities were obtained from nine mammalian species: rat, mouse, horse, sheep, guinea pig, hamster, rabbit, dog and man. 2. Kinetic constants (Km and Vmax) using hippuryl-L-histidyl-L-leucine as substrate and inhibitory constants (I50 and Ki) for captopril were determined for the serum ACE of each species. 3. There were important differences in the kinetic and inhibitory constants (Kms went from 6.6 mM to 1.21 mM for hamster and guinea pig; I50 ranged from 2100 nM to 3 nM for mouse and sheep) as well as differences in enzyme activity of the different spe...
Kuchiiwa S, Kuchiiwa T, Suzuki T.The orbits of 13 mammalian species (pig, sika deer, domestic sheep, horse, cat, fox, racoon dog, marten, rat, rabbit, crab-eating macaque, japanese macaque and man) were stained with silver nitrate and dissected under a dissecting microscope with special attention to the presence and location of the accessory ciliary ganglion. Some preparations were stained with thionin and examined as whole-mounts in a transmission microscope. The accessory ciliary ganglion was present in all 13 species, although the number and degree of development varied greatly from species to species. The accessory ciliar...
Schmidt-Oechtering GU.The anaesthesia with Xylazine and Ketamine in 24 foals is described. Special qualities of this form of anaesthesia and dosages for foals of different age are discussed. The combination of Xylazine and Ketamine is well suited for the anaesthesia of foals of all age and risk-groups. The induction takes place quickly and calmly, without signs of cardiorespiratory depression. The maintenance of anaesthesia is possible, without any problem, by repeated injection with Xylazine and Ketamine, as well as by inhalation anaesthesia with volatile anaesthetics. The recovery is short; the animals rise swift...
Weaver BM, Staddon GE, Pearson MR.The blood content of tissue in eight anaesthetized sheep and three anaesthetized horses was measured using chromium labelled autologous red blood cells. 2. Approximately half the total blood volume was found to be distributed within the body tissues and, with the exception of the spleen and fat, the distribution was similar in these two species.
Colles CM.This paper describes the application of foil strain gauges to the hoof wall, and the use of measuring equipment to monitor weightbearing and changes in hoof shape in shod and unshod horses. It concludes that the systems can detect hoof movement and that results are reproducible. It is also concluded that the use of a conventional nailed on iron shoe restricts flexion and spreading of the hoof wall at the ground surface, but has little effect on the degree of expansion of the heels of the foot.
Brown MP, Gronwall RR, Houston AE.Six healthy adult mares were each given an oral loading dose of ormetoprim(OMP)-sulfadimethoxine (SDM) at a dosage of 9.2 mg of OMP/kg and 45.8 mg of SDM/kg, followed by four maintenance doses of 4.6 mg of OMP/kg and 22.9 mg of SDM/kg, at 24 h intervals. Ormetoprim and SDM concentrations were measured in serum, synovial fluid, peritoneal fluid, cerebrospinal fluid, urine and endometrium. The highest mean serum OMP concentration was 0.92 micrograms/mL 0.5 h after the first dose; the highest mean SDM concentration was 80.9 micrograms/mL 8 h after the first dose. The highest mean synovial fluid c...
Rugh KS, Garner HE, Miramonti JR, Hatfield DG.Myocardial and haemodynamic responses to strenuous treadmill exercise were monitored with chronically implanted instrumentation in seven physically untrained ponies. In two other ponies, haemodynamics were monitored using a conventional catheter technique. During exercise (mean +/- sem heart rate = 203 +/- 3 beats/min), left ventricular peak systolic ahd end-diastolic blood pressure significantly increased from 125 +/- 2 to 208 +/- 6 mmHg and from 29 +/- 1 to 58 +/- 3 mmHg, respectively (P less than 0.05). Peak positive first derivative of left ventricular pressure (dP/dt) was also increased s...
Dudan F, Hirni H.Since 1980 techniques specifically designed to treat human neonatal diseases have also started to be applied to ill or premature equine newborns. These techniques will be described and their application to the most common equine neonatal disorders will be discussed. Such techniques include: post-natal cardiopulmonary resuscitation, exogenous thermal support, administration of broad spectrum antibiotics after diagnostic studies, supplemental oxygen therapy and mechanical ventilation, intravenous fluid and electrolyte therapy, blood component transfusion and total parenteral nutrition.
Andersson-Eklund L, Andersson L, Sandberg K.A study was carried out to attempt to explain the basis of the association between the Es locus and starting proportion in Swedish Trotters which had been observed previously. The effect of Es genotype on starting proportion has diminished among horses born in the late 1970s. There are indications that the incidence of leg lesions varies between Es genotypes. If this is true, it is possible that the decreasing effect of the Es locus on starting proportion is due to the environmental changes which have been made at race tracks in the early 1980s to reduce the strain on the legs of the trotters....
Bollwein A, Hänichen T.The cervical vertebral column of 103 horses of different age (42 weeks old fetus to 23 years) were examined with respect to age-related changes of the intervertebral disks. On gross examination the cervical intervertebral disks in the horse miss a pulpy nucleus but consist of a fibrocartilaginous tissue only, which is in contrast to literature. Age-related degenerative lesions as disintegration of connective tissue fibers leading to partial or complete loss of connection between the disks were found. In the more severe cases a yellow discoloration of the separated disks could be seen. Incidenc...
van Dijk S, Wensing T.1. The serum lipoprotein pattern was studied in four horses, four ponies and in three high producing lactating and three non-lactating cows. The lipoprotein pattern was estimated with a combination of the preparative ultracentrifugation and the heparin-manganese precipitation technique. 2. The lipid composition of the lipoproteins of horse, pony, lactating cow and non-lactating cow was determined. 3. In all three species more than 50% of serum total lipids was found in the HDL fraction. 4. The mean chylomicron fraction in horse and pony was 3.1%. In the cow it varied from 1.5 to 2.5%. 5. Betwe...
Valpotić I, Kastelan M, Rudolf M, Gerencer M, Jukić B, Basić I.The percentage of T and B lymphocytes in the peripheral blood of horses chronically infected with equine infectious anaemia (EIA) virus was determined and the results were compared with the percentage of these cells in healthy uninfected horses. Cells with membrane receptors for sheep erythrocytes (T and active T lymphocytes) were determined by E and A rosette techniques, while cells with receptors for the C3b component of complement and those with receptors for mouse erythrocytes (B lymphocytes), were determined by the EAC rosette method. The percentage of Fe positive cells was assayed by the...
Reef VB, Lalezari K, De Boo J, van der Belt AJ, Spencer PA, Dik KJ.Pulsed-wave Doppler echocardiography was performed on 30 clinically normal 1- to 6-year-old racing Standardbreds. There were 13 females, 13 geldings, and 4 stallions. Cardiac disease was not detected with M-mode, 2-dimensional real-time or pulsed-wave Doppler echocardiography. Normal flow velocities for right and left atrial outflow, right and left ventricular outflow, the aorta, and pulmonary artery were determined. Peak flow velocities for right and left atrial outflow occurred during the rapid filling phase and were higher toward the mitral valve (mean, 0.70 +/- 0.24 m/s) than toward the tr...
Essén-Gustavsson B, McMiken D, Karlström K, Lindholm A, Persson S, Thornton J.Five horses were studied during a five-week regime of controlled intensive daily training on a high-speed treadmill followed by five weeks of detraining. Muscle biopsies were taken weekly from both the right and left gluteus muscle and from the sternocephalicus muscle before, and at the end of, the training and detraining periods. Histochemical and biochemical analyses of the sternocephalicus muscle showed no metabolic adaptation with either training or detraining. No significant differences were observed in any of the analysed parameters in the gluteus muscle between contralateral sites. Glyc...
Scott DW.Pemphigoid (from the Greek “resembling pemphigus”) has been recognized in humans for many years. The occurence of pemphigoid in domestic animals is a much more recent observation. In the dog, bullous pemphigoid was first documented in 1978.1 Equine bullous pemphigoid was originally reported in 1981.2 The purpose of this article is to review pemphigoid in domestic animals, compare the disease with its human counterpart, and alert the physician to an exciting area for comparative dermatologic research.
Perry LR, Butler AJ, John E, Martinson S, Buote M, Foote K, Burton S, Stoughton WB.Two equine patients presented separately with severe abdominal distention, colic, lethargy, and decreased appetite. An ante-mortem diagnosis of lymphoma was reached in each case based on peritoneal fluid cytology. Due to a poor prognosis, the horses were humanely euthanized. Post-mortem examination with histology and immunohistochemistry confirmed both cases as lymphoma: alimentary B-cell lymphoma of the distal jejunum and cecum in one case, and T-cell lymphoma of the cecum in the second case. Both cases exhibited extensive metastasis with peritoneal and pleural serosae covered in small nodule...
Craig TM, Courtney CH.The kind of parasites a horse acquires depends upon its environment. Because patterns of transmission vary greatly with climate and management, no one worming program has universal applications. This article discusses epidemiology and control of equine parasites in the southern United States, where climates vary from warm temperate to subtropical and from humid in the southeast to arid in the southwest.
Stabenfeldt GH, Hughes JP, Wheat JD, Evans JW, Kennedy PC, Cupps PT.The effect of hysterectomy on ovarian activity was studied
in four mares. The cyclic secretion pattern of plasma progestins normally
observed in the intact mare was interrupted by hysterectomy. Follicular
activity was observed in all four hysterectomized mares, in spite of pro-
longed luteal activity, with a large number of follicles attaining ovulatory
size without the occurrence of ovulation. Some ovulations were observed
at irregular intervals in two out of four hysterectomized mares in spite
of plasma progestin levels which ranged from 2 to 6 ng/ml. While all
ovulations which occur...
Greene S, Keegan R, Brown J, Kingston J, Bayly WM.This study evaluated the effects of pre-exercise frusemide administration and hypertonic saline (H) infusion during anaesthesia on arterial pH, blood gases and electrolytes in 6 Thoroughbred horses anaesthetised immediately post exercise. Horses received either frusemide (F) (0.5 mg/kg, i.v.) or a saline placebo (P) injection 4 h prior to treadmill exercise. Exercise consisted of a 3 min warm-up at 40% VO2max followed by exercise to fatigue. Detomidine (40 micrograms/kg, i.v.) was given within 5 min of stopping and followed 5 min later by zolazepam-tiletamine (1.25 mg/kg, i.v.) to induce anaes...
Ducharme NG, Viel L, Partlow GD, Hulland TJ, Horney FD.The purpose of this project was to attempt restoration of abduction of a recently denervated left dorsal cricoarytenoid muscle in the horse by anastomosing the first cervical nerve to the abductor branch of the left recurrent laryngeal nerve. Ten horses were used in the study. In six horses the left recurrent laryngeal nerve was transected and ligated while the ventral branch of the left first cervical nerve was anastomosed to the abductor branch of the left recurrent laryngeal nerve. The remaining four horses also had the left recurrent laryngeal nerve transected and ligated but had no nerve ...
Bell BT, Baker GJ, Foreman JH, Abbott LC.The frequency of communication between the tarsometatarsal and distal intertarsal joints was investigated in 27 horses and 12 ponies. After the injection of diluted latex into the tarsometatarsal joints using the plantarolateral approach, the horses and ponies were walked for 200 meters. Latex was found in the distal intertarsal joints of 19 of 73 tarsi (26% communication) at necropsy. In 3 tarsi, latex was also found in the proximal intertarsal and tarsocrural joints.
Frei S, Geyer H, Hoey S, Fuerst AE, Bischofberger AS.To determine scapular cortex thickness, distal scapular bone density and describe the exact suprascapular nerve course to evaluate the best plate position for the fixation of supraglenoid tubercle fractures in horses. Methods: Twelve equine cadaveric shoulders were examined with computed tomography. Computed tomography morphometry and density measurements (Hounsfield units [HU]) of the scapula were recorded. Statistical comparisons were made between the cranial and caudal aspects of the scapula. Dissection of each shoulder was performed and the suprascapular nerve course was described morphome...
Ginther OJ, Pinaffi FL, Rodriguez MB, Duarte LF, Beg MA.During the luteolytic period in mares, the peak of 65% of pulses of a PGF2α metabolite (PGFM) and the peak of a pulse of PRL have been reported to occur at the same hour. It is unknown whether the synchrony reflects an effect of PGF2α on PRL or vice versa. Controls, a flunixin meglumine (FM)-treated group (to inhibit PGF2α), and a bromocriptine-treated group (to inhibit PRL), were used at 14 days postovulation in June and in September (n = 6 mares/group/mo). Blood samples were collected hourly from just before treatment (Hour 0) to Hour 10. Concentrations of PGFM in the FM group were lower ...
Scheel J, Duswald KH, Ring J, Seifert J, Scholz S, Brendel W.Eight mongrel dogs received a standard daily i.v. infusion of 20 mg/kg b.w. deaggregated horse-anti-dog-lymphocyte-globulin (ALG) and additional prednisolone (1 mg/kg b.w. daily i.v.) over a maximum period of 82 days following pretreatment with deaggregated normal horse IgG. No sensitization against horse protein was observed during therapy of afterwards as proved by lack of humoral antibodies against horse antigens, maintained lymphopenia, good compatibility, longterm prolongation of xenogeneic skin graft survival (85.6+/-20.6 days, n=8' untreated controls 12.5+/-1.3 days, n=4) and longterm s...
Roberts MC, Seawright AA, Ng JC.Phenylmercuric acetate (PMA) was administered orally to a horse over a period of 27 weeks (190 days) at a dose rate of 0.4 mg Hg/kg per day. The effects produced were consistent with those of chronic inorganic mercury intoxication. The clinical features included masseter muscle atrophy, difficulty in prehension and mastication, malodorous breath, reduced appetite and weight loss, and reflected significant pathological changes involving the buccal, mandibular and dental tissues. Renal dysfunction was evident terminally and there was degeration and necrosis of the proximal tubular epithelium. Ne...
Maier-Bock H, Ehrlein HJ.During a gradually increasing exercise test heart rates were determined in healthy animals and in 2 groups of sick horse. These included 31 animals with a chronic pulmonary disorder and 5 with chronic heart disease. The alteration in heart rate was correlated with the clinical signs exhibited. In the horses with lung disease there was a close correlation between the stage of the diseases and the heart rate during the exercise test. In 3 animals with heart valve disease there was no apparent difference in heart rate compared with healthy horses. On the other hand the exercising heart rate of ho...
Taylor FG, Mair TS, Brown PJ.Equine steatitis is a rare condition which is usually reported in foals. A case of generalised steatitis in an adult pony mare is described and compared with steatitis in other species. It is concluded that the condition resembled that recorded in foals but that its aetiopathogenesis remains obscure.
Louw JP, Meyer S, Schröder J.The anthelmintic efficacy of a 44.5% paste formulation of cambendazole was evaluated in a critical trial performed on 5 horses and a donkey. A dosage of 20 mg/kg showed reduction of mean parasite burdens as follows: Strongylinae greater than 99%; Cyathostominae 94%; immature and adult Oxyuris equi 89 and greater than 99%; Probstmayria vivipara greater than 99% and Habronema muscae 97%. Parascaris equorum and Anoplocephala perfoliata were present in small numbers in individual animals only, and while all were removed by treatment, the small numbers did not justify calculation of a percentage ef...
Hennessy SE, Muurlink MA, Anderson GA, Puksmann TN, Whitton RC.To evaluate the long-term racing prognosis for Thoroughbred racehorses with displaced versus non-displaced fractures of the pelvis identified by scintigraphy. Methods: Retrospective case analysis. Methods: Medical records of 31 Thoroughbred racehorses presenting to the University of Melbourne Equine Centre with fractures of the pelvis that were identified by scintigraphy were reviewed. Pelvic fracture site was determined and defined as displaced or non-displaced based on ultrasound and/or radiographic findings. Race records were analysed for each horse, with a minimum of 24 months' follow-up, ...
Pauli BU, Rossi Straub R.A trabecular adenoma of the pars intermedia of the hypophysis was seen in a 13-year-old half-bred mare that presented symptoms corresponding to Cushing's disease of man. The spindle-shaped tumor cells were for the most part ‘light’, seldom ‘dark’. Both of them were characterized by well-developed rough endoplasmic reticulum, small Golgi apparatus, and typical secretory granules with a diameter of about 200 μm. The pituitary tumor and the symptoms were accompanied by increased plasma adenocorticotrophic hormone (ACTH) and by bilateral hyperplasia of the adrenal cortex. The tumor cells ...
Flieger S, Sławomirski J, Boratyński Z, Jastrzebski M.Two medullae oblongatae of horses were cut into 15 microns cross-sections and stained according to the modified method of Nissel. The lateral motor nucleus lies in the lateral and median part of the ventral column of spinal cord grey matter. It adjoins medially nucleus motorius medialis of the spinal ventral column. Cells of this nucleus occur both along the whole lumbar and sacral segment of the spinal cord. In the lateral motor nucleus three cell groups are distinguished - median, basal and lateral. The latter is divided in some segments into subgroups - dorsal and ventral. Along the nucleus...