Influence of baclofen on temperature-sensitive neurons in chick hypothalamus.
The effects of the GABA(B)-receptor agonist baclofen on neuronal tonic activity (firing rate) and temperature sensitivity (temperature coefficient, TC) of neurons in the preoptic area/anterior hypothalamus (PO/AH) have been examined in chick brain slices, using extracellular recordings. The tonic activity of both warm-sensitive and cold-sensitive neurons, as well as temperature-insensitive neurons, was significantly inhibited by superfusion with baclofen (1 microM). It is clearly evident from the present study that there was an increasing trend in warm-sensitive neurons and a significant (p<0.05) increase in TC of cold-sensitive neurons. Relatively high percentage (31.5%) of chick PO/AH neurons was determined as cold sensitive by present investigation. Particularly, GABA(B) mechanisms modify temperature sensitivity of the PO/AH neurons and thus modulation of temperature sensitivity in PO/AH is involved in the control of body temperature.
Yakimova
K
K
Department of Pharmacology, Faculty of Medicine, Medical University, Sofia, Bulgaria. kyakim@medfac.acad.bg
Sallagundla
N
N
Tzschentke
B
B
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D001418:Baclofen / Q000494:pharmacology; D002645:Chickens / Q000502:physiology*; D018755:GABA Agonists / Q000494:pharmacology; D058786:GABA-B Receptor Agonists; D066298:In Vitro Techniques; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D011301:Preoptic Area / Q000187:drug effects / Q000502:physiology*; D018080:Receptors, GABA-B / Q000502:physiology; D013696:Temperature; D013697:Thermosensing / Q000187:drug effects / Q000502:physiology*
D018755:GABA Agonists; D058786:GABA-B Receptor Agonists; D018080:Receptors, GABA-B; D001418:Baclofen