A computational study of astrocytic glutamate influence on post-synaptic neuronal excitability
Fig 10
Frequency of postsynaptic firing due to combination of synaptic, extrasynaptic and intrinsic currents.
Simulation with [Glu]ast,eq = 1.5mM, 5mM, and 10mM (left to right). (a) Frequency of postsynaptic firing due to the glutamate release both directly from the presynaptic neuron and from the astrocyte, (b) Frequency of postsynaptic firing due to synaptic glutamate-mediated currents and (c) Frequency of postsynaptic firing due to astrocytic-released-activated currents. Presynaptic activation given as (above b) bar and (above c) SIC. Frequency of postsynaptic firing was calculated using rectangular windowing of length 2 sec, 0.1 overlap. Increasing [Glu]ast,eq results in higher baseline postsynaptic firing to identical presynaptic stimuli determined by longer time course of synaptic glutamate and thus enhanced synaptic-mediated currents. Increasing [Glu]ast,eq also results in longer intervals of high (~60Hz where [Glu]ast,eq = 10mM) frequency, longer lasting postsynaptic depolarisations as a result of enhanced gliotransmission.