Firing cell repertoire during carbachol‐induced theta rhythm in rat hippocampal formation slices

Abstract

One hundred and seven cells were recorded extracellularly in hippocampal formation (HPC) slices during carbachol-induced theta. The data obtained provided evidence of a population of HPC neurons which, when activated cholinergically, participate in the generation of in vitro theta. The activity patterns of in vitro recorded theta-related cells were shown to be similar to those of theta-related cells recorded in vivo and cells recorded in vitro during cholinergically induced theta, and non-theta intervals were successfully classified according to previously developed criteria for in vivo recorded theta-related cells. The current in vitro experiments showed that, in addition to theta-on and theta-off cells, the HPC contained cells that were probably involved in programming the appearance and duration of theta epochs and the intervals between theta epochs. These novel types of cells were termed 'gating cells'.

Ampakines cause sustained increases in brain-derived neurotrophic factor signaling at excitatory synapses without changes in AMPA receptor subunit expression

“…Results obtained with a cholinergic agonist favor this latter idea. Carbachol increases rhythmic neuronal firing in hippocampal slices (Colgin et al, 2003, Konopacki et al, 2006) and induces BDNF via AMPAR-independent mechanisms (Lauterborn et al, 2003). Carbachol down-regulated GluR1 and GluR2 mRNA and protein levels in field CA1 with the same magnitude and time course as did the ampakine CX614.…”

Cell discharge correlates of posterior hypothalamic theta rhythm recorded in anesthetized rats and brain slices

“…According to our previous studies (Konopacki et al, ; Kowalczyk et al, ,b), some neurons were also classified as gating cells if they met one of the following criteria: (i) the cell discharges occurred precisely in the beginning and at the end of each theta epoch (gating cell A); (ii) the cell began to discharge just before the transition from non‐theta interval/LIA into the theta epoch (gating cell B); (iii) the cell began to discharge just after the transition from the theta epoch into non‐theta interval/LIA (gating cell C).…”

Development of NMDA-induced theta rhythm in hippocampal formation slices

“…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.…”

“…Numerous studies carried out in vivo and in vitro have demonstrated that the appearance of theta rhythm requires a certain level of excitation of local neuronal networks (Bland and Colom, 1993;Bland, 2008;Cobb et al, 1995;Konopacki et al, 2006;Konopacki and Gołębiewski, 1993;Yoder and Pang, 2005). 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.…”

“…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.…”