Arousal-related associative response characteristics of dorsal lateral geniculate nucleus neurons during acoustic Pavlovian fear conditioning.
This research determined whether fear-conditioned, acoustic stimuli induce thalamic arousal reflected in associative responses in dorsal lateral geniculate nucleus (dLGN) neurons. Rabbits received a Pavlovian discriminative fear conditioning procedure in which one tone conditioned stimulus (CS +) was always paired with an aversive unconditioned stimulus (US) and another tone (CS-) was never paired with the US. Responses of single dLGN neurons to random CS+ and CS- presentations were then recorded. Nine of 15 recorded neurons demonstrated significantly greater firing during the CS+ versus the CS-. Their spontaneous activity demonstrated tonic firing during increased neocortical arousal and burst firing during decreased neocortical arousal. The results demonstrate that dLGN neurons show associative responses to fear-conditioned, acoustic stimuli and present a model for investigating the neural circuits by which such stimuli affect sensory processing at the thalamic level.
Cain
M E
ME
Department of Psychology, University of Vermont, Burlington 05405, USA. mcain@zoo.uvm.edu
Kapp
B S
BS
Puryear
C B
CB
D000818:Animals; D001143:Arousal / Q000502:physiology*; D001245:Association Learning / Q000502:physiology*; D001307:Auditory Perception / Q000502:physiology*; D001931:Brain Mapping; D003214:Conditioning, Classical / Q000502:physiology*; D004569:Electroencephalography; D005239:Fear / Q000502:physiology*; D005260:Female; D005829:Geniculate Bodies / Q000502:physiology*; D008564:Membrane Potentials / Q000502:physiology; D019579:Neocortex / Q000502:physiology; D009474:Neurons / Q000502:physiology; D011817:Rabbits