The basal forebrain (BF) plays a major role in cortical and behavioural arousal, attention, as well as learning and memory. These processes are thought to be regulated by cholinergic, GABAergic and glutamatergic neurons that populate the BF and project widely through the neuraxis. These three neuronal groups may not be entirely exclusive to each other, and it has been proposed that some cholinergic BF neurons might co-release glutamate. Consistent with this suggestion, our previous study using dual immunofluorescence for choline acetyltransferase (ChAT) and vesicular glutamate transporter 3 (VGLUT3) in rat showed that ChAT+/VGLUT3+ neurons were present in the ventral pallidum (~36%), magnocellular preoptic area (~13%), substantia innominata (~25%) and magnocellular basal nucleus (~25%)[Poulin et al. SFN Abstr. 950.5, 2004]. In the same study we also showed that cholinergic axon terminals in the basolateral amygdaliod nucleus (BLA), but not in other targets of BF cholinergic projections, were co-immunoreact...