Effects of neurotoxic lesions in the posterior hypothalamic region on psychomotor activity and learning.

Article date: 1994/11/1

PubMed ID: 2755282

Journal name: Agents and actions (ISSN: 0065-4299)


Histamine (HA) acts as a neurotransmitter and/or neuromodulator in mammalian brain. Central HA has been found to be involved in the regulation of behavioral, cognitive, neurovegetative, neuroendocrine and neuroimmune functions. In this study we have evaluated psychomotor activity (PMA) and passive avoidance behavior (PAB) in rats with bilateral neurotoxic lesions in the posterior hypothalamic region (PHR) (L), where histaminergic neurons are located, and in sham-operated rats (S), two weeks after neurosurgery. In an open-field paradigm, lesioned rats showed higher PMA scores than sham-operated animals. However, L rats exhibited a significant decrease in PMA on consecutive days (motor habituation) similar to that found in S rats. In a maze paradigm, in which the animals had to learn to stay on a neutral platform in order to avoid a 1.5 mA electric footshock during 10 trails, no significant differences were observed between L and S rats on the task performance. According to the present results, it seems that bilateral neurotoxic lesions in the PHR induced hyperactivity with no apparent effects on PAB, suggesting that neuronal HA might be involved, directly and/or by influencing arousal/alertness-mediated mechanisms, in the regulation of PMA processes.

Author List: Alvarez X A, Franco A, Fernández-Novoa L, Cacabelos R

Publication Types: Journal Article; Research Support, Non-U.S. Gov't

Substances mentioned in the article: Ibotenic Acid; Histamine;

Mesh terms: Analysis of Variance; Animals; Behavior, Animal/drug effects; Female; Histamine/physiology; Hypothalamus/drug effects; Ibotenic Acid/pharmacology; Learning/drug effects; Psychomotor Performance/drug effects; Rats; Rats, Sprague-Dawley;

Citations: - 1751006

2755282.txt · Last modified: 2018/11/20 14:26 (external edit)