Abstract
The present study investigated the effects of intracebroventricular injections of 192 IgG-saporin in 7-day-old rats on (i) ultrasound vocalizations (USVs) on postnatal day (pnd) 13 following isolation and reunion with the mother and (ii) fear conditioning on pnd 18-19 recording both freezing and other behavioural responses as well as USVs. On pnd 13 lesioned and control pups showed comparable USV baseline values; a brief reunion with the mother induced a significant increase in USVs in all rats (maternal potentiation). On pnd 18, during the fear conditioning training, 192 IgG-saporin rats emitted a lower number of USVs. On pnd 19 all rats showed a stronger conditioned response (with full inhibition of locomotion) to auditory than to contextual cues. Surprisingly, lesioned rats showed a stronger fear-conditioned response to contextual cues than controls. These results suggest that early selective removal of the cholinergic basal forebrain paradoxically enhances hippocampally dependent fear-conditioned responses on pnd 19.
Publication types
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Research Support, N.I.H., Extramural
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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Animals, Newborn
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Antibodies, Monoclonal / pharmacology
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Association Learning / drug effects
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Association Learning / physiology
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Avoidance Learning / drug effects
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Avoidance Learning / physiology
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Choline O-Acetyltransferase / metabolism
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Cholinergic Agents / pharmacology
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Cholinergic Fibers / drug effects
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Cholinergic Fibers / physiology*
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Conditioning, Classical / drug effects
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Conditioning, Classical / physiology*
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Fear / drug effects
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Fear / physiology*
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Female
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Hippocampus / drug effects
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Hippocampus / metabolism
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Immunotoxins / pharmacology
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Male
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Maternal Deprivation
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N-Glycosyl Hydrolases / pharmacology
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Neocortex / drug effects
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Neocortex / metabolism
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Prosencephalon / cytology
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Prosencephalon / drug effects
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Prosencephalon / physiology*
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Random Allocation
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Rats
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Rats, Wistar
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Ribosome Inactivating Proteins, Type 1
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Saporins
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Stress, Psychological / physiopathology
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Ultrasonics
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Vocalization, Animal / drug effects
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Vocalization, Animal / physiology*
Substances
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192 IgG-saporin
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Antibodies, Monoclonal
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Cholinergic Agents
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Immunotoxins
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Ribosome Inactivating Proteins, Type 1
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Choline O-Acetyltransferase
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N-Glycosyl Hydrolases
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Saporins