Spatial Memory Impairments Following Immunotoxic Lesion of GABAergic Neurons of the Nucleus Basalis Magnocellularis

摘要

The central aim of the present study was to investigate the modulation of spatial memory function by the GABAergic cells of the nucleus basalis magnocellularis (NBM) using immunotoxin GAT1-SAP for immunolesion of GABAergic neurons. In current study rats were trained in a visible platform version of the Morris water maze in which either a place or cue strategy could be used to escape successfully. Of the 24 rats that underwent behavioral testing, 12 received immunotoxic GAT1-SAP injections and 12 received mouse saporin (control group) injections to the NBM. The NBM lesioned rats as control rats rapidly learned to escape to the visible platform and reached the 6-7 s asymptote on day 2. But statistical analysis showed no significant difference between groups (P = 0.954) in visible platform trials and significant difference between NBM and control (P < 0.001) groups in hidden platform trials. The data obtained in the control and NBM-lesioned animals in the present study, demonstrate that decreased place-bias in NBM-lesioned rats compared to the control rats was significant. The NBM lesioned rats acquired the visible platform version of the water maze task but failed to learn the platform location in space. When the visible platform was moved to a new location they often swam directly to it. These findings suggest the role of NBM GABAergic cortical projection neurons in processing information about the spatial environment.