+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

Ventral hippocampal muscimol disrupts context-specific fear memory retrieval after extinction in rats



Ventral hippocampal muscimol disrupts context-specific fear memory retrieval after extinction in rats



Hippocampus 16(2): 174-182



Research aimed at understanding Pavlovian fear memory extinction has yielded considerable insight into the conditions under which fear memories may become inhibited. After extinction, Pavlovian fear memory retrieval is context-specific. Fear memories are not expressed in the extinction context, but they are expressed in every other context. Research indicates that the dorsal hippocampus mediates the context-specific expression of fear memory, but the role of the ventral hippocampus in mediating this process is unknown. Insofar as the ventral hippocampus is involved in the acquisition and expression of both context and tone fear, we asked whether GABA systems in the ventral hippocampus mediate context-specific fear memory retrieval after extinction. Experiment 1 showed that ventral hippocampal inactivation with muscimol disrupted context-specific fear memory retrieval. Experiment 2 showed that rats infused with muscimol can discriminate a context in which they were shocked from a neutral context. Nonetheless, they do appear to have a mild impairment in this task. Experiment 3 showed that ventral hippocampal muscimol did not disrupt locomotor activity, but did result in a slight increase in freezing and grooming, an effect that cannot explain the context-specific retrieval deficit demonstrated in experiment 1. These data are consistent with a role for the ventral hippocampus in mediating context-specific fear memory retrieval.

Please choose payment method:






(PDF emailed within 0-6 h: $19.90)

Accession: 012739818

Download citation: RISBibTeXText

PMID: 16358312

DOI: 10.1002/hipo.20144


Related references

Hippocampal inactivation disrupts contextual retrieval of fear memory after extinction. Journal of Neuroscience 21(5): 1720-1726, 2001

Hippocampal inactivation disrupts context specific extinction of fear a within subjects study. Society for Neuroscience Abstract Viewer & Itinerary Planner : Abstract No 83 16, 2002

Hypofunction of the dorsal hippocampal NMDA receptors impairs retrieval of memory to partially presented foreground context in a single-trial fear conditioning in rats. European Neuropsychopharmacology 16(4): 241-247, 2006

Acute nicotine disrupts consolidation of contextual fear extinction and alters long-term memory-associated hippocampal kinase activity. Neurobiology of Learning and Memory 145: 143-150, 2017

Fear memory formation can affect a different memory: fear conditioning affects the extinction, but not retrieval, of conditioned taste aversion (CTA) memory. Frontiers in Behavioral Neuroscience 8: 324, 2014

Memory retrieval before or after extinction reduces recovery of fear in adolescent rats. Learning and Memory 20(9): 467-473, 2013

Alteration of synaptic transmission in the hippocampal-mPFC pathway during extinction trials of context-dependent fear memory in juvenile rat stress models. Synapse 63(9): 805-813, 2009

The ventral hippocampus and fear conditioning in rats. Different anterograde amnesias of fear after tetrodotoxin inactivation and infusion of the GABA(A) agonist muscimol. Experimental Brain Research 139(1): 39-52, 2001

Reversible inactivation of medial prefrontal cortex disrupts the retrieval of fear extinction. Society for Neuroscience Abstract Viewer & Itinerary Planner : Abstract No 199 8, 2003

An Additional Prior Retrieval Alters the Effects of a Retrieval-Extinction Procedure on Recent and Remote Fear Memory. Frontiers in Behavioral Neuroscience 11: 259, 2017

Low-frequency stimulation of the hippocampus following fear extinction impairs both restoration of rapid eye movement sleep and retrieval of extinction memory. Neuroscience 170(1): 92-98, 2010

Hippocampal low-frequency stimulation and chronic mild stress similarly disrupt fear extinction memory in rats. Neurobiology of Learning and Memory 89(4): 560-566, 2008

Muscimol inactivation of the dorsal hippocampus impairs contextual retrieval of fear memory. Journal of Neuroscience 19(20): 9054-9062, 1999

Inactivation of the dorsal or ventral hippocampus with muscimol differentially affects fear and memory. Brain Research 1353: 145-151, 2010

Administration of corticosterone after memory reactivation disrupts subsequent retrieval of a contextual conditioned fear memory: dependence upon training intensity. Neurobiology of Learning and Memory 89(2): 178-184, 2008