Persistent posttetanic depression at cerebellar parallel fiber to Purkinje cell synapses.

Plasticity at the cerebellar parallel fiber to Purkinje cell synapse may underlie information processing and motor learning. In vivo, parallel fibers appear to fire in short high frequency bursts likely to activate sparsely distributed synapses over the Purkinje cell dendritic tree. Here, we report that short parallel fiber tetanic stimulation evokes a ∼7-15% depression which develops over 2 min and lasts for at least 20 min.

Immunohistochemical characterization of calcitonin gene-related peptide in the trigeminal system of the familial hemiplegic migraine 1 knock-in mouse.

Introduction: Familial hemiplegic migraine type 1 (FHM-1) is caused by mutations in the CACNA1A gene, with the R192Q mutation being the most common. Elevated calcitonin gene-related peptide (CGRP) levels in acute migraine and clinical trials using CGRP receptor antagonists suggest CGRP-related mechanisms are important in migraine.

Methods: Wild-type and R192Q knock-in mice were anaesthetized and perfused.

The ammonium-induced increase in rat brain lactate concentration is rapid and reversible and is compatible with trafficking and signaling roles for ammonium.

The glutamate-glutamine shuttle requires a flux of fixed N from neurons to astrocytes. The suggestion that some or all of this N is ammonium has received support from reports that ammonium (as NH(4)(+)) rapidly enters astrocytes. Ammonium might also help control astrocyte energy metabolism by increasing lactate production.

Dopamine inhibits trigeminovascular transmission in the rat.

Objective: Clinical evidence, such as premonitory or postdromal symptoms, indicate involvement of dopamine in the pathophysiology of migraine.

Methods: To study the influence of dopamine on nociceptive trigeminovascular neurotransmission, we first determined using immunohistofluorescence that dopamine receptors were present in the rat trigeminocervical complex; then using extracellular recording techniques, we examined whether dopamine modulates cell firing in the trigeminocervical complex.

Results: We identified a discrete population of D1 receptors (median, 11; interquartile range, 7-30 neurons/hemisection) predominantly located in the deep laminae and a more abundant population of D2 receptors (median,75; interquartile range, 30-99 neurons/hemisection) that were evenly distributed in the trigeminocervical complex.

Co-treatment with riluzole and GDNF is necessary for functional recovery after ventral root avulsion injury.

Unilateral avulsion of lumbar ventral roots kills approximately 50% of injured motoneurons within 2 weeks of surgery. Immediate treatment involving surgical reimplantation of the ventral root (VRI) or intrathecal glial cell line-derived neurotrophic factor (GDNF) delivery or intraperitoneal injection of riluzole for 2 weeks ameliorates motoneuron death to 80% of control but combining the different treatment paradigms did not further enhance survival except when GDNF was combined with VRI. At 3 months, all combined treatments provided a neuroprotective effect compared to avulsion only, but the neuroprotective effect of surgical reimplantation alone was not maintained unless combined with riluzole and GDNF treatment.