Neonatal basal forebrain cholinergic hypofunction affects ultrasonic vocalizations and fear conditioning responses in preweaning rats.
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.
Ricceri
Laura
L
Section of Behavioural Neuroscience, Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità, Rome, Italy. laura.ricceri@iss.it
Cutuli
Debora
D
Venerosi
Aldina
A
Scattoni
Maria Luisa
ML
Calamandrei
Gemma
G
D000818:Animals; D000831:Animals, Newborn; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D001245:Association Learning / Q000187:drug effects / Q000502:physiology; D001362:Avoidance Learning / Q000187:drug effects / Q000502:physiology; D002795:Choline O-Acetyltransferase / Q000378:metabolism; D018678:Cholinergic Agents / Q000494:pharmacology; D002799:Cholinergic Fibers / Q000187:drug effects / Q000502:physiology*; D003214:Conditioning, Classical / Q000187:drug effects / Q000502:physiology*; D005239:Fear / Q000187:drug effects / Q000502:physiology*; D005260:Female; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D000922:Immunotoxins / Q000494:pharmacology; D008297:Male; D008426:Maternal Deprivation; D009699:N-Glycosyl Hydrolases / Q000494:pharmacology; D019579:Neocortex / Q000187:drug effects / Q000378:metabolism; D016548:Prosencephalon / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D054789:Ribosome Inactivating Proteins, Type 1; D000076985:Saporins; D013315:Stress, Psychological / Q000503:physiopathology; D014465:Ultrasonics; D014828:Vocalization, Animal / Q000187:drug effects / Q000502:physiology*
C085696:192 IgG-saporin; D000911:Antibodies, Monoclonal; D018678:Cholinergic Agents; D000922:Immunotoxins; D054789:Ribosome Inactivating Proteins, Type 1; D002795:Choline O-Acetyltransferase; D009699:N-Glycosyl Hydrolases; D000076985:Saporins