Faculty Collaboration Database

Effects of complete immunotoxin lesions of the cholinergic basal forebrain on fear conditioning and spatial learning. Hippocampus 2004;14(2):244-54

Date

04/22/2004

Pubmed ID

15098729

DOI

10.1002/hipo.10169

Scopus ID

2-s2.0-0842322454 (requires institutional sign-in at Scopus site)   58 Citations

Abstract

Administration of muscarinic cholinergic antagonists such as scopolamine impairs the acquisition of contextual fear conditioning, but the role of the basal forebrain (BF) cholinergic system in consolidation is unclear. To test the hypothesis that BF cholinergic neurons are critical for acquisition and consolidation of fear conditioning, male Sprague-Dawley rats with 192 IgG-saporin lesions of the entire cholinergic BF made either before or after fear conditioning were tested for conditioned fear to context and tone by assessing freezing and 22 kHz ultrasonic vocalization (USV) responses. Spatial learning in a 1-day water maze task provided a comparison for effects of the BF lesions on fear conditioning. In the test phase, neither pre-training nor posttraining BF lesions affected freezing to the context or tone. During both training and testing, pre-lesioned rats were impaired in production of USVs associated with fear. Postlesioned rats emitted fewer USVs only during testing. Acquisition of a spatial water maze task was mildly impaired in lesioned rats, although probe trial and cued performance was unimpaired. Nevertheless, these data suggest that conditioned fear-induced USVs are more sensitive to the loss of BF cholinergic neurons than is conditioned fear-induced freezing. The failure of BF cholinergic lesions to impair contextual fear conditioning indicates that scopolamine-induced impairments in fear conditioning may not be mediated by affecting cholinergic input to the hippocampus and neocortex.

Author List

Frick KM, Kim JJ, Baxter MG

Author

Karyn Frick BA,MA,PhD Professor in the Psychology department at University of Wisconsin - Milwaukee

MESH terms used to index this publication - Major topics in bold

Animals
Antibodies, Monoclonal
Choline O-Acetyltransferase
Conditioning, Operant
Cues
Fear
Glutamate Decarboxylase
Immunohistochemistry
Immunotoxins
Male
Maze Learning
Memory
N-Glycosyl Hydrolases
Parasympathetic Nervous System
Prosencephalon
Rats
Rats, Sprague-Dawley
Ribosome Inactivating Proteins, Type 1
Vocalization, Animal