Lateral Asymmetry in Activation of Hypothalamic Neurons with Unilateral Amygdaloid Seizures

• Published in: Epilepsia (Copenhagen) Vol. 41; no. 1; pp. 34 - 41
• Main Authors: Silveira, D. C., Klein, P., Ransil, B. J., Liu, Z., Hori, A., Holmes, G. L., LaCalle, S., Elmquist, J., Herzog, A. G.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.01.2000; Blackwell
• Subjects: Amygdala - pathology; Animals; Biological and medical sciences; Epilepsy; Female; Fos; Headache. Facial pains. Syncopes. Epilepsia. Intracranial hypertension. Brain oedema. Cerebral palsy; Hypothalamus; Hypothalamus - pathology; Immunohistochemistry; Kindling; Lateral asymmetry; Medical sciences; Nervous system (semeiology, syndromes); Neurology; Neurons - pathology; Rats; Rats, Sprague-Dawley; Reproductive; Seizures - pathology; Immunohistochemistry; Nervous system diseases; Reproduction diseases; Pathophysiology; Rat; Rodentia; Complex partial epilepsy; Activation; Hypothalamus; Cerebral disorder; Female genital diseases; Pathology; Vertebrata; Mammalia; Neuron; Animal; Central nervous system disease; Complication; Temporal lobe epilepsy; Female
• ISSN: 0013-9580; 1528-1167
• DOI: 10.1111/j.1528-1157.2000.tb01502.x

Purpose: Reproductive disorders are unusually frequent among women with temporal lobe seizures. The particular type of disorder may be related to the laterality and focality of epileptiform discharges. Here we examined whether unilateral amygdaloid seizures activate hypothalamic neurons involved in reproductive function and reproductive endocrine secretion in female rats and whether such activation shows lateral asymmetry. Methods: Numbers of Fos‐immunoreactive (Fos‐ir) neurons in various hypothalamic regions were compared for three groups of animals: (a) unilateral amygdala‐kindled, (b) implanted but unstimulated, and (c) unimplanted. Results: Fos‐ir neurons showed strong ipsilateral occurrence in the medial preoptic, ventrolateral part of the ventromedial, and ventral premammillary nuclei, sexually dimorphic regions involved in reproductive endocrine regulation. No significant lateral asymmetry was observed for other investigated hypothalamic regions. Conclusions: Unilateral amygdaloid seizures activate hypothalamic neurons that regulate reproductive endocrine secretion in a laterally asymmetric fashion. This may explain the clinical association of different reproductive endocrine disorders with left and right temporal epileptiform discharges.