Postnatal development of intrinsic GABAergic rhythms in mouse hippocampus

At clinically relevant concentrations the anaesthetic/amnesic thiopental but not the anticonvulsant phenobarbital interferes with hippocampal sharp wave-ripple complexes

“…SPWs generation depends on excitatory and inhibitory synaptic transmission mediated by glutamatergic non-NMDA [28,29,31,62,76] and GABA A receptors [28,29,62] respectively, and intense activation of inhibitory interneurons has been observed in vivo [15,47,48,77] and in vitro [78]. SPW-associated ripple oscillation is a high-frequency (100–200 Hz) field event generated from the interaction between pyramidal cells and inhibitory interneurons [8,16,46-48,79], with proposed prominent role of the interneurons [46-48].…”

Hypoglycemia-induced alterations in hippocampal intrinsic rhythms: Decreased inhibition, increased excitation, seizures and spreading depression

“…In both standard and thick slices bSPWs disappear when the GABA A receptor is blocked with bicuculline (Wong et al, 2005;Wu et al, 2005bWu et al, , 2006. We hypothesize that the initial transient increase in bSPW activity during low glucose perfusion is due to an unsustained increase in GABA release from the presynaptic terminal (Tossman et al, 1985), while the ensuing decrease in bSPW could be explained through several mechanisms including presynaptic GABA depletion (Huberfeld et al, 2011;Zhang et al, 2012), increased GABA uptake and catabolism, postsynaptic receptor malfunction or simply due to shift of the Cl-reversal potential (Karlocai et al, 2014;Leinekugel et al, 1999) associated with the progressive depolarization induced by hypoglycemia.…”

“…Additionally, we describe the effects of hypoglycemia on two intrinsic rhythms observed in the thick hippocampal slice; baseline sharpwaves (bSPW) which are strongly correlated with GABA A inhibitory postsynaptic potentials (IPSPs) on CA3 pyramidal cells (Ellender et al, 2010;Hajos et al, 2013;Maier et al, 2003;Wong et al, 2005), and the large amplitude sharp waves (LASW) (El-Hayek et al, 2013;Wu et al, 2002Wu et al, , 2005bWu et al, , 2009), a designation given to N 300 μV SPW-like events associated with spontaneous increased excitatory neurotransmission and pyramidal cell firing observed spontaneously, or induced by tetanic stimulation in mouse isolated thick hippocampal slices. Here, we show that hypoglycemia depressed bSPW and enhanced LASW along with a progressive neuronal membrane depolarization and glutamate receptor activation, phenomena associated with seizure initiation in the CA3 region, often followed by spreading depression in the CA1 region.…”

Maternal Deprivation Influences Pup Ultrasonic Vocalizations of C57BL/6J Mice

“…Benner suggested that early deprivation can induce competitive subordinance and impaired reversal learning with altered functions of the limbic and frontal cortices in adult C57BL/6 mice [14]. However, the effect of MD in early life, particularly the neonatal days during which multiple neural systems are established [15,16], has rarely been investigated, which may be partially due to the lack of parameters that can be quantitatively analyzed in very young rodents.…”