We have reported previously that a selective metabotropic glutamate receptor (mGluR) agonist, (1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid (1S,3R-ACPD), caused a slow membrane depolarization in rat dorsolateral septal nucleus (DLSN) neurons. Using single electrode voltage-clamp recording methods, we now investigate the pharmacological properties of the receptor that mediates ACPD-induced m...

A fundamental question in vision neuroscience is how parallel processing of Retinal Ganglion Cell (RGC) signals is integrated at the level of the visual thalamus. It is well-known that parallel ON-OFF pathways generate output signals from the retina that are conveyed to the dorsal lateral geniculate nucleus (dLGN). However, it is unclear how these signals distribute onto thalamic cells and how ...

Stereoisomers of 1-amino-2-phosphonomethylcyclopropanecarboxylic acid (APCPr), conformationally restricted analogues of L-AP4 (2-amino-4-phosphonobutyric acid), have been prepared and evaluated at recombinant group III metabotropic glutamate receptors. They activate these receptors over a broad range of potencies. The most potent isomer (1S,2R)-APCPr displays a similar pharmacological profile a...

Synaptic depression of evoked EPSCs was quantified with stimulation frequencies ranging from 0.2 to 100 Hz at the single CNS synapse formed by the calyx of Held in the rat brainstem. Half-maximal depression occurred at approximately 1 Hz, with 10 and 100 Hz stimulation frequencies reducing EPSC amplitudes to approximately 30% and approximately 10% of their initial magnitude, respectively. The t...

The effect of metabotropic glutamate receptor (mGluR) activation on vasopressin (VP) and oxytocin (OT) release was evaluated using explants of the hypothalamoneurohypophysial system. (+/-)-1-Aminocyclopentane-trans-1,3-dicarboxylic acid (t-ACPD), an agonist at groups I and II mGluRs, increased VP and OT release in a concentration-dependent manner. A role for group I mGluRs in VP and OT release ...

The excitatory amino acid antagonists D,L-2-amino-5-phosphonovalerate (D,L-AP5), its isomers D-(-)-AP5 and L-(+)-AP5, D,L-2-amino-4-phosphonobutyrate (AP4), D,L-2-amino-7-phosphonoheptanoate (AP7), beta-D-aspartylaminomethylphosphonic acid (ASP-AMP), cis-2,3-piperidinedicarboxylic acid (cis-PDA), and gamma-D-glutamylaminomethylsulphonic acid (GAMS) were tested for their ability to produce a phe...

We investigated two siblings, born to consanguineous parents, with neurological features reminiscent of adaptor protein complex 4 (AP4) deficiency, an autosomal recessive neurodevelopmental disorder characterized by neonatal hypotonia that progresses to hypertonia and spasticity, severe intellectual disability speech delay, microcephaly, and growth retardation. Yet, both children also presented...

Spontaneous miniature glycinergic inhibitory postsynaptic currents (mIPSCs) in mechanically dissociated rat sacral dorsal commissural nucleus (SDCN) neurons attached with intact glycinergic presynaptic nerve terminals and evoked IPSCs (eIPSCs) in the slice preparation were investigated using nystatin-perforated patch and conventional whole cell recording modes under the voltage-clamp conditions...

We have explored the mechanisms of mossy fiber long-term potentiation (LTP) at autapses in single-cell cultures of guinea pig hippocampal dentate granule cells. L-AP4-sensitive, but not insensitive, cells responded to a brief tetanus with a sustained potentiation in the synaptic responses. The induction of this LTP appeared identical to that observed in hippocampal mossy fiber synapses in situ,...