Ascending and descending convergent inputs to neurons in the nucleus parabrachialis of the rat: an intracellular study.
Responses of the nucleus parabrachialis neurons (PBN) to electrical stimulation of the lateral hypothalamus (HL), central nucleus of the amygdala (Ac), dorsolateral funicullus in the spinal cord (SC), mediocaudal nucleus tractus solitarius (NTS), and substantia nigra (SN) were investigated in anesthetized rats by intracellular recording technique. Convergent excitatory postsynaptic potentials (EPSPs) were evoked on 8 of 36 neurons tested by both HL and NTS stimulation. The EPSPs evoked by HL stimulation were characterized as monosynaptic in 4 neurons. The EPSPs evoked by SC stimulation were characterized as monosynaptic in 2 of 36 neurons, moreover, these neurons were also antidromically activated by HL stimulation. Stimulation of Ac evoked EPSPs on 10 of 36 cells tested; 8 demonstrated to be monosynaptic. In addition, IPSP evoked by SN stimulation and EPSP evoked by NTS stimulation converged on three neurons. The results indicate that ascending and descending inputs converge on lateral PBN neurons.
Granata
A R
AR
Department of Pharmacology, College of Medicine, University of Tennessee, Memphis 38163.
D000758:Anesthesia; D000818:Animals; D004558:Electric Stimulation; D004566:Electrodes; D005071:Evoked Potentials / Q000502:physiology; D006651:Histocytochemistry; D006735:Horseradish Peroxidase; D008297:Male; D009475:Neurons, Afferent / Q000502:physiology*; D009476:Neurons, Efferent / Q000502:physiology*; D011149:Pons / Q000033:anatomy & histology / Q000166:cytology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012018:Reflex / Q000187:drug effects; D013569:Synapses / Q000502:physiology
D006735:Horseradish Peroxidase