A distinct group of non-cholinergic neurons along the mid-line of the septum and within the rat medial septal nucleus

The septum is a critical and integral component of the limbic brain that serves as a link between diverse brain structures while being necessary for human cognition and emotionality. A major anatomical component of the septum is designated as the medial septum/diagonal band of Broca complex (MS/DB). A primary focus of much research has been to investigate cholinergic neurons within the MS/DB, as these are the rodent brain's main source of acetylcholine to the cortex and hippocampus. On the other hand, we have chosen to investigate a specific group of neurons that lie on the midline of the MS/DB in an area distinguished anatomically as the medial septal nucleus (MSN). Based on somatic morphology and electrophysiological characteristics we conclude that these neurons, characterized into three different types, are non-cholinergic. (c) 2006 Elsevier Ireland Ltd. All rights reserved.