Neurotransmitter glutamatergic

Glutamatergic neurons. Neurons using glutamate and/or glutamate-Zn complexes as a neurotransmitter. Glutamatergic neurons constitute about 50% of entire brain neurons. 

Cory-Slechta DA. 1995a. Relationships between lead-induced learning impairments and changes in dopaminergic, cholinergic, and glutamatergic neurotransmitter system functions. Annu Rev Pharmacol Toxicol 35 391-415. 

The basal forebrain is an important way station in the activation of the cerebral cortex from the reticular activating system. AMPA and NMDA injections into the basal forebrain increase wakefulness and reduce sleep (Cape Jones, 2000 Manfridi et al, 1999), effects that are blocked by AMPA and NMDA receptor antagonists (Manfridi et al, 1999). The excitatory cortical projections of the basal forebrain have long been considered purely cholinergic, but many basal forebrain neurons that project to the cortex are now known to contain Glu, which may function as a co-transmitter or even as the primary excitatory neurotransmitter (Manns et al, 2001). The basal forebrain also affects vigilance via synapses to HCT cells in the lateral hypothalamus some of these synapses are glutamatergic (Henny Jones, 2006). 

Hertz, L. and Schousboe, A. (1987) Primary cultures of GABAergic, and glutamatergic neurons as model systems to study neurotransmitter functions. I. Differentiated cells, in Model Systems of Development and Aging of the Nervous System (Vemadakis, A., Privat, A., Lauder, J. M., Timiras, P. S and Giacobini, E eds.), M. Nijhoff Publishing Company, Boston, MA, pp. 19-31. 

Responses in the dopamine system are more complex (see chapter by Balfour, this volume). Repeated nicotine injections resulted in enhanced extracellular DA levels in the NAc (Benwell and Balfour 1992, 1997), but not in the striatum (Benwell and Balfour 1997). Analysis of the precise placement of dialysis probes has revealed differential responses to drugs of abuse, including nicotine, between the NAc core (ventral striatum) and shell (Di Chiara 2002 Balfour 2004 Wonnacott et al. 2005 see chapter by Balfour, this volume). Moreover, the sensitised neurotransmitter responses observed in the hippocampus and NAc were markedly attenuated if rats received a constant infusion of a low level of nicotine (Benwell and Balfour 1997). Thus, transient peaks of nicotine appear capable of sensitising some brain pathways with respect to catecholamine release, but the responses may be mitigated by lower sustained plasma concentrations, possibly due to desensitisation. The extent that presynaptic nAChRs contribute to this process in vivo is unclear presynaptic a7 nAChRs on glutamatergic afferents to the VTA merit attention as potential mediators of sensitisation (see Sect. 2.2.2). 

The first group includes the glutamatergic and GABAergic systems. These two classes of neurons are by far more prevalent and more widely distributed than any other neurotransmitter system in the human brain. The major functional implication of such widespread distribution is that the modulation of glutamatergic and GABAergic neurotransmission affects many neural systems. 

GABA is the major inhibitory neurotransmitter in the CNS. Similar to the modulation of glutamatergic receptors, the application of ligands that can strengthen or weaken GABAergic activity has widespread effects. 

---