Sexually dimorphic effects of hippocampal cholinergic deafferentation in rats.
To determine whether the basal forebrain-hippocampal cholinergic system supports sexually dimorphic functionality, male and female Long-Evans rats were given either selective medial septum/vertical limb of the diagonal band (MS/VDB) cholinergic lesions using the neurotoxin 192 IgG-saporin or a control surgery and then postoperatively tested in a set of standard spatial learning tasks in the Morris water maze. Lesions were highly specific and effective as confirmed by both choline acetyltransferase/parvalbumin immunostaining and acetylcholinesterase histochemistry. Female controls performed worse than male controls in place learning and MS/VDB lesions failed to impair spatial learning in male rats, both consistent with previous findings. In female rats, MS/VDB cholinergic lesions facilitated spatial reference learning. A subsequent test of learning strategy in the water maze revealed a female bias for a response, relative to a spatial, strategy; MS/VDB cholinergic lesions enhanced the use of a spatial strategy in both sexes, but only significantly so in males. Together, these results indicate a sexually dimorphic function associated with MS/VDB-hippocampal cholinergic inputs. In female rats, these neurons appear to support sex-specific spatial learning processes.
Jonasson
Zachariah
Z
Neuroscience Program, Department of Psychology, Harvard University, William James Hall, 33 Kirkland Street, Cambridge, MA 02138, USA. jonasson@wjh.harvard.edu
Cahill
Jonathan F X
JF
Tobey
Rachel E
RE
Baxter
Mark G
MG
D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D000911:Antibodies, Monoclonal / Q000633:toxicity; D001522:Behavior, Animal / Q000187:drug effects*; D002452:Cell Count / Q000379:methods; D002795:Choline O-Acetyltransferase / Q000378:metabolism; D018678:Cholinergic Agents / Q000633:toxicity; D005260:Female; D006624:Hippocampus / Q000378:metabolism*; D007150:Immunohistochemistry / Q000379:methods; D000922:Immunotoxins / Q000633:toxicity; D008297:Male; D018782:Maze Learning / Q000187:drug effects / Q000502:physiology; D009699:N-Glycosyl Hydrolases; D010320:Parvalbumins / Q000378:metabolism; D051381:Rats; D020318:Rats, Long-Evans; D054789:Ribosome Inactivating Proteins, Type 1; D000076985:Saporins; D012686:Septal Nuclei / Q000187:drug effects / Q000502:physiology; D012688:Septum Pellucidum / Q000187:drug effects / Q000502:physiology; D012727:Sex Characteristics; D012737:Sex Factors; D013037:Spatial Behavior / Q000187:drug effects
C085696:192 IgG-saporin; D000911:Antibodies, Monoclonal; D018678:Cholinergic Agents; D000922:Immunotoxins; D010320:Parvalbumins; D054789:Ribosome Inactivating Proteins, Type 1; D002795:Choline O-Acetyltransferase; D009699:N-Glycosyl Hydrolases; D000076985:Saporins; D000109:Acetylcholine