Sexually dimorphic effects of hippocampal cholinergic deafferentation in rats

Neuroscience Program, Department of Psychology, Harvard University, William James Hall, 33 Kirkland Street, Cambridge, MA 02138, USA.
European Journal of Neuroscience (Impact Factor: 3.18). 01/2005; 20(11):3041-53. DOI: 10.1111/j.1460-9568.2004.03739.x
Source: PubMed


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.

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    • "Conversely, it's also been shown that hippocampal cholinergic neuron lesions are associated with facilitated learning in a spatial discrimination task [115]. Also, chemical cholinergic blockade in the hippocampus promotes place learning on the Morris water maze [116], and this has been demonstrated in both male and female rats [117] suggesting that the role of hippocampal acetylcholine in spatial learning is not as straightforward as initially thought. Multiple memory systems are also employed by humans to navigate their environment and solve tasks. "
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    03/2014; %(1):35-50. DOI:10.2478/s13380-014-0209-7
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    • "This level of self-movement cue processing deficit spares initial response learning in spatial tasks; however, disruptions in performance would be expected on tasks that eliminated environmental cues (i.e., Dark-probe) or place environmental and self-movement cues in conflict (i.e., New-probe). Previous work has shown that infusion of 192-IgG-saporin into the MS/VDB spares place learning in the water maze (Baxter and Gallagher 1996; Jonasson et al. 2004; Vuckovich et al. 2004; Frielingsdorf et al. 2006) and impairs homing accuracy during the Dark-and New-probes of the food-hoarding paradigm (Martin and Wallace 2007). "
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    Brain Structure and Function 08/2012; 218(5). DOI:10.1007/s00429-012-0449-7 · 5.62 Impact Factor
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    • "Moreover, the results from the few studies to date, which have examined the effects of biological sex on learning strategy, suggest that the male advantage in spatial performance emerges from a greater reliance on a place learning strategy [50] [51] [52] [53] [54]. However, inconsistencies in results between studies that have employed similar learning paradigms [50] [51] [52] [53], as well as ambiguous learning strategy classification techniques [54], make drawing definitive conclusions about the relationship between biological sex and learning strategy difficult. Therefore, the current study sought to clarify and "
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