Effects of propofol on GABAergic and glutamatergic transmission in isolated hippocampal single nerve-synapse preparations

Neural mass model-based tracking of anesthetic brain states

“…Although the UKF applied to the JR model approach produced reasonable OAA/S score classification testing knowledge that the IPSP amplitude and rate constant are effected by propofol concentration (Kitamura et al, 2003;Wang et al, 2004;Bieda & MacIver, 2004;Ying & Goldstein, 2005;McCarthy et al, 2008;Wang, 2009;Yue et al, 2011;Wakita et al, 2013;Hutt, 2013). This decision puts more contraints on the UKF estimation process to fit the data.…”

“…This approach has been successfully applied to the tracking of seizure dynamics through feeding single channel EEG into the UKF to invert the JR model and estimate its state and up to 5 parameters including the four PSP parameters A, a, B and b (Freestone et al, 2013). Here the same methods are employed, however, the focus is on estimating 100 the key parameters that are most effected by increases in propofol concentration, the IPSP amplitude B and IPSP rate constant b (Collins, 1988;Krasowski et al, 1998;Bai et al, 1999Bai et al, , 2001Siegwart et al, 2002;Dong & Xu, 2002;Kitamura et al, 2003;Wang et al, 2004;Feng & Macdonald, 2004;Bieda & MacIver, 2004;Ying & Goldstein, 2005;McCarthy et al, 2008;Drexler et al, 2009;Wang, 2009;Yue et al, 2011;Wakita et al, 2013;Hutt, 2013). These two parameters are considered to primarily capture the shape of the EEG amplitude spectrum, while a third parameter,…”

“…All other model parameters are treated as constants. Limiting the parameters to be estimated as θ = [ B b µ ] T somewhat constrains the ability of the JR model to fit the EEG data, however, it enables evaluation of whether the IPSP amplitude B and IPSP rate constant b increase and decrease, respectively, as is observed when the concentration of propofol anesthetic increases (Kitamura et al, 2003;Wang et al, 2004;Bieda & MacIver, 2004;Ying & Goldstein, 2005;McCarthy et al, 110 2008; Wang, 2009;Yue et al, 2011;Wakita et al, 2013;Hutt, 2013). This then can act as a benchmark for more complex and accurate models of the EEG linked to propofol anesthesia for the purposes of anesthesia monitoring and simultaneous estimation of known parameter changes.…”

“…The actual degree of variation of IPSP parameters with propofol concentration observed physiologically is highly dependent on the brain region studied, the neurotransmittor receptors considered, and the experimental preparation, whether it be cell cultures or isolated cells (Krasowski et al, 1998;Bai et al, 1999Bai et al, , 2001Siegwart et al, 2002;Dong & Xu, 2002;Feng & 470 Macdonald, 2004;Drexler et al, 2009;Yue et al, 2011;Wakita et al, 2013), or tissue slices (Collins, 1988;Bieda & MacIver, 2004;Wang et al, 2004;Ying & Goldstein, 2005;Wang, 2009). In tissue slices, measurements focus more directly on PSP-level parameters and appear to indicate a greater sensitivity to propofol of the IPSP rate constant than for IPSP amplitude, however, there are still observed variations in both parameters depending on the preparation (Collins, 1988;Bieda & MacIver, 2004;Wang et al, 2004;Ying & Goldstein, 2005;Wang, 2009).…”

Inhibition of Excitatory Synaptic Transmission in Hippocampal Neurons by Levetiracetam Involves Zn2+-Dependent GABA Type A Receptor–Mediated Presynaptic Modulation

“…Focal electrical stimulation of single boutons synapsing onto an isolated CA3 neuron induced fast inward currents that were completely and reversibly abolished by adding 102 20 mM CNQX, AMPA/KA receptor antagonist, indicating clearly that they are AMPA/KA receptor-mediated eEPSCs (Henze et al, 2002, Wakita et al, 2013. Paired-pulse stimulation at a frequency of 0.2 Hz produced paired EPSCs in which the second eEPSC amplitude (P 2 ) was approximately 138.0 6 5.0% (n 5 66 neurons [boutons]) of the first EPSC amplitude (P 1 ).…”