Effects of GRF on paraventricular neurons in slices of guinea-pig hypothalamus.
Growth hormone releasing factor (GRF) applied by iontophoresis, pressure, and in the perfusate, increased (14.81%) or decreased (45.92%) the firing of paraventricular neurons extracellularly recorded from guinea-pig hypothalamic slices. Effects were similar whatever the mode of application and were elicited in the nanomolar range. They persisted in high Mg2+ medium, indicating a post-synaptic action of the peptide. Of the neurons 27.40% had a phasic activity suggestive of vasopressin neurons and were recorded in the vasopressinergic parts of the paraventricular nucleus. The effect of GRF on these phasic neurons was a reduction of firing. The present results demonstrate the action of GRF on paraventricular neurons and suggest that this action is inhibitory on vasopressin neurons.
Poulain
P
P
Carette
B
B
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D005260:Female; D013007:Growth Hormone-Releasing Hormone / Q000494:pharmacology*; D006168:Guinea Pigs; D009474:Neurons / Q000187:drug effects* / Q000502:physiology; D010286:Paraventricular Hypothalamic Nucleus / Q000187:drug effects* / Q000502:physiology; D011930:Reaction Time / Q000187:drug effects / Q000502:physiology; D014667:Vasopressins / Q000502:physiology
D014667:Vasopressins; D013007:Growth Hormone-Releasing Hormone