BACKGROUND Spasticity arises from hyperexcitability of the neural stretch reflex arc secondary to injury of the corticospinal tract. In response to injury, the density of glutamatergic inputs from afferent 1A fibers to motor neurons increases dramatically and adaptive changes occur in the morphology of microglia cells in the spinal cord. SUMMARY Involvement of the endocannabinoid system in pa...

Glutamatergic projections from the parabrachial nucleus to the central amygdala are implicated in pain transmission. In this issue of Neuron, Delaney et al. identify a new form of adrenergic modulation at these synapses, demonstrating that noradrenaline-induced suppression of glutamate release is mediated by a decrease in the number of sites of synaptic transmission without changes in probabili...

Glutamate is the main excitatory neurotransmitter in the central nervous system (CNS) and is a major player in complex brain functions. Glutamatergic transmission is primarily mediated by ionotropic glutamate receptors, which include NMDA, AMPA and kainate receptors. However, glutamate exerts modulatory actions through a family of metabotropic G-protein-coupled glutamate receptors (mGluRs). Dys...

The nucleus accumbens, a brain region involved in motivation, attention, and reward, receives substantial glutamatergic innervation from many limbic structures. This excitatory glutamatergic input plays an integral role in both normal and pathophysiological states. Despite the importance of glutamatergic transmission in the nucleus accumbens, the specific receptor subtypes that mediate glutamat...

Synaptic modulation and long-term synaptic changes are thought to be the cellular correlates for learning and memory (Madison et al., 1991; Aiba et al., 1994, Goda and Stevens, 1996). The hippocampus is a center for learning and memory that receives abundant cholinergic innervation and has a high density of nicotinic acetylcholine receptors (nAChRs) (Wada et al., 1989; Woolf, 1991). We report t...