Maturation of many synapses of the CNS is characterized by a reduction in initial release probability and associated alterations in short-term plasticity (STP). We investigated the role of tonic activity of metabotropic glutamate receptors (mGluRs) in this process in glutamatergic synapses of rat neocortex. Consistent with previous reports, STP of excitatory postsynaptic currents (EPSCs) evoked...

Effects of 5-hydroxytryptamine (5-HT) on EPSPs and EPSCs in the rat dorsolateral septal nucleus (DLSN) were examined in the presence of GABA(A) and GABA(B) receptor antagonists. Bath application of 5-HT (10 microm) for 5-10 min increased the amplitude of the EPSP and EPSC. (+/-)-8-hydroxy-2-(di-N-propylamino)tetralin hydrobromide (10 microm), an agonist for 5-HT1A and 5-HT7 receptors, did not f...

Multiple trains of high-frequency synaptic stimulation evoke long-term potentiation (LTP) of synaptic transmission in hippocampal area CA1, which has been correlated with hippocampal long-term memory and requires the activation of cAMP-dependent protein kinase (PKA). To assess whether postsynaptic PKA is necessary for the expression of LTP, we made prolonged whole-cell voltage-clamp recordings ...

Familial hemiplegic migraine type 1 (FHM1) is caused by gain-of-function mutations in CaV2.1 (P/Q-type) Ca(2+) channels. Knockin (KI) mice carrying the FHM1 R192Q missense mutation show enhanced cortical excitatory synaptic transmission at pyramidal cell synapses but unaltered cortical inhibitory neurotransmission at fast-spiking interneuron synapses. Enhanced cortical glutamate release was sho...

Using whole cell patch-clamp recording from hypoglossal motoneurons of a neonatal rat brain slice preparation, we investigated short-term changes in synaptic transmission mediated by GABA or glycine. In 1.5 mM extracellular Ca(2+) [Ca(2+)](o), pharmacologically isolated GABAergic or glycinergic currents were elicited by electrical stimulation of the reticular formation. At low stimulation frequ...

We examined the ability of different G protein subunits to inhibit the activity of human alpha1B and alpha1E Ca2+ channels stably expressed in human embryonic kidney (HEK) 293 cells together with beta1B and alpha2Bdelta Ca2+ channel subunits. Under normal conditions, Ca2+ currents in alpha1B-expressing cells showed little facilitation after a depolarizing prepulse. However, when we overexpresse...

Chronic insomnia is a poorly understood disorder. Risk factors for developing chronic insomnia are largely unknown, yet disturbances in arousal seem to accompany the disorder. We here investigate whether insomnia patients and control participants differ with respect to one operationalization of arousal, i.e. cortical excitability. A method to directly investigate the excitability level of the h...

Postactivation depression of the Hoffmann (H) reflex is associated with a transient period of suppression following activation of the reflex pathway. In soleus, the depression lasts for 100-200 ms during voluntary contraction and up to 10 s at rest. A reflex root evoked potential (REP), elicited after a single pulse of transcutaneous stimulation to the thoracolumbar spine, has been shown to exh...

47 48 Partially isolated “undercut” neocortex with intact pial circulation is a well-established 49 model of post-traumatic epileptogenesis. Results of previous experiments showed a 50 decreased frequency of miniature inhibitory postsynaptic currents (mIPSCs) in layer V 51 pyramidal (Pyr) neurons of undercuts (Li and Prince 2002). We further examined 52 possible functional abnormalities in GABA...

Partially isolated "undercut" neocortex with intact pial circulation is a well-established model of posttraumatic epileptogenesis. Results of previous experiments showed a decreased frequency of miniature inhibitory postsynaptic currents (mIPSCs) in layer V pyramidal (Pyr) neurons of undercuts. We further examined possible functional abnormalities in GABAergic inhibition in rat epileptogenic ne...