Window effect of temperature on carbachol-induced theta-like activity recorded in hippocampal formation in vitro

Hippocampal Theta in the Newborn Rat Is Revealed under Conditions That Promote REM Sleep

“…Perhaps the most significant and unique feature of the present experiment was the provisioning of a thermoneutral test environment in which body temperatures of infants at the ages used here are maintained at ϳ37°C (Blumberg et al, 1997). This feature of the experiment may be important for two reasons: First, hippocampal electrophysiological activity is influenced by local brain temperature (Andersen and Moser, 1995) and hippocampal slices from adult rats can be induced to exhibit theta-like activity only within a narrow thermal window of 33-37°C (Kowalczyk et al, 2001). Second, testing in an appropriate thermal environment permits the expression of many prolonged periods of REM (or active) sleep (Sokoloff and Blumberg, 1998), thereby maximizing the number and duration of artifact-free periods of hippocampal recording.…”

Propagating Wave and Irregular Dynamics: Spatiotemporal Patterns of Cholinergic Theta Oscillations in Neocortex In Vitro

“…1) in agreement with the results obtained by Lukatch and MacIver (1997). These oscillations can be distinguished from epileptiform spikes in the same tissue: epileptiform spikes had high-amplitude (ϳ1 mV) and low-repetition frequency (0.5-1.5 Hz), whereas theta oscillations had a low-amplitude (ϳ0.5 mV) and high frequency (5-14 Hz) (Kowalczyk et al 2001). Staining with the dye did not change the frequency, duration, or the amplitude of the theta oscillations recorded by the local field potential electrode (data not shown).…”

Development of NMDA-induced theta rhythm in hippocampal formation slices

“…Depending on the concentration of the drug used, the synchrony of the neuronal population and the magnitude of the field oscillation vary from epileptic patterns to in vitro theta oscillations (Konopacki et al, 1987;Konopacki and Gołębiewski, 1993). As was earlier reported, the in vitro HPC theta state and epileptiform discharges can be modulated by a specific temperature of the bathing medium (Kowalczyk et al, 2001) and simultaneous manipulations of cholinergic excitation and GABAergic inhibition (Gołębiewski et al, 1996;Konopacki and Gołębiewski, 1993;Konopacki, 1998). Altogether, these findings indicate that the appearance of epileptic mode and the transition into the theta mode could be specifically programmed by the activity of the local hippocampal neuronal network (Kowalczyk et al, 2001).…”

“…The production of theta oscillations in a brain slice preparation takes place in the presence of bath perfusion with cholinergic agonists (Kazmierska et al, 2012;Konopacki et al, 1987Konopacki et al, , 2006Konopacki, 1996Konopacki, , 1998Kowalczyk et al, 2001), or simultaneous perfusion with GABA A and GABA B antagonists (Konopacki, 1998). Konopacki et al (1987) observed that when hippocampal slices are bathed in a solution containing the muscarinic agonist carbachol, short bursts of field oscillation at 4-15 Hz occur intermittently.…”

“…Many years of research conducted with the use of models of HPC slice preparations have allowed us to determine the specific role of the cholinergic (Kazmierska et al, 2012;Konopacki et al, 1987Konopacki et al, , 2006Konopacki, 1998;Kowalczyk et al, 2001) and GABAergic systems (Gołębiewski et al, 1996;Konopacki and Gołębiewski, 1993;Konopacki et al, 1997) in providing the adequate level of neuronal excitation necessary for theta to appear. Our findings are supported by a large body of data from other laboratories, in which carbachol-induced theta rhythm in hippocampal slices Cappaert et al, 2009;Fellous and Sejnowski, 2000;McQuiston, 2010;Natsume and Kometani, 1999) and urethanized rats (Kinney et al, 1998;Leung and Péloquin, 2010;Monmaur et al, 1997;Yoder and Pang, 2005) were observed.…”