Seizure, neurotransmitter release, and gene expression are closely related in the striatum of 4-aminopyridine-treated rats

Long-lasting dephosphorylation of connexin 43 in acute seizures is regulated by NMDA receptors in the rat cerebral cortex

“…On the other hand, MK-801 decreased swelling at every time point, implying that it was largely caused by excessive glutamate release. This long-lasting (150 min from the injection of 4-AP) significant elevation of extracellular glutamate has been proven by our previous experiments in 4-AP seizures (22). Therefore, we believe that glial swelling in GTCS has two phases: Phase 1 depends on elevated extracellular glutamate and causes swelling through the entry of Na + and Ca 2+ into the cell (42), and Phase 2 (post-3 h) is mediated by the opening of the hemichannels through the dephosphorylation process and the uncoupling of the astrocytes (15,39).…”

Immunohistochemistry of cerebellar seizures: Mossy fiber afferents play an important role in seizure spread and initiation in the rat

“…Important observation of the present experiments was that the activation of the cerebellar granule cells lasted significantly longer than the activation of the hippocampal granule cells (Mihály et al, 2001), the activation of neurons of the striatum (Kovács et al, 2003) and the activations of the neurons of the neocortex (Mihály et al, 2005). The cerebellar granule cell is a glutamatergic neuron, which has NMDA and AMPA receptors on its dendritic tree (Geurts et al, 2003;Koutsouraki et al, 2013).…”

“…The 4-AP also releases transmitters other than glutamate, such as GABA (Kovács et al, 2003). We suggest the role of GABAergic Golgi neurons which can inhibit the granule cell activation (D'Angelo and De Zeeuw, 2008).…”

“…Our previous studies proved that c-fos protein is a reliable marker of neuronal hyperactivity in 4-AP-induced acute seizures (Mihály et al, 2001(Mihály et al, , 2005Szakács et al, 2003;Kopniczky et al, 2005). During the 4-AP seizure, the increase in the number of c-fosIR cell nuclei displayed a characteristic pattern: maximum numbers of the c-fosIR cells were seen at 1 h after 4-AP treatment in the neocortex, dentate gyrus and striatum (Kovács et al, 2003;Mihály et al, 2001Mihály et al, , 2005. According to our RT-PCR measurements in the neocortex, the c-fos mRNA expression dynamics showed a similar pattern, maximum expression at 1 h (Mihály et al, 2005).…”

“…The activation of neuronal networks in the cerebellar cortex was followed by the immunohistochemical detection of the synaptic glutamate induced c-fos expression during seizures (Mihály et al, 2001(Mihály et al, , 2005Kovács et al, 2003;Szakács et al, 2003). Supposing that the afferent mossy fiber system plays a primary role in the activation of the cerebellar cortex, we also performed the transection of the middle cerebellar peduncle (MCP) in adult rats.…”