What is EPSC amplitude?
amplitude of the second EPSC as the peak current measured relative to. the baseline before the first stimulus (i.e., without subtracting the first. EPSC tail), a definition different to that of Trussell et al (1993).
What is miniature EPSC?
Miniature EPSC (mEPSC) analysis indicates pre- rather than post-synaptic effects of LY354740. A: Original current traces of mEPSC recorded in an individual CeLC neuron in the presence of TTX (1 μM) show that LY354740 (1 μM) reduces frequency but not amplitude of mEPSCs.
What are miniature excitatory postsynaptic currents?
Term: mini excitatory postsynaptic potential. Definition: A process that leads to a temporary increase in postsynaptic potential due to the flow of positively charged ions into the postsynaptic cell, induced by the spontaneous release of a single vesicle of an excitatory neurotransmitter into the synapse.
What is a mEPSC?
Abstract. Prior synaptic or cellular activity influences degree or threshold for subsequent induction of synaptic plasticity, a process known as metaplasticity. Thus, the continual synaptic activity, spontaneous miniature excitatory synaptic current (mEPSC) may correlate to the induction of long-term depression (LTD).
How is mEPSC measured?
- calculate the average mEPSC interval and compare the two groups with a t-test.
- calculate the average instantaneous frequency for each cell and perform a t-test.
- measure average frequency for each cell (total number of events/time) and compare with t-test.
What is decay time Epsc?
The rise time of EPSC was 2.0 ± 0.2 msec, the time constant of decay was 3.6 ± 0.5 msec, and the mean amplitude of EPSC was −5.5 ± 1.0 nA at the resting potential level (−53.8 ± 1.4 mV) and at 36°C.
What causes mini EPSPs?
EPSPs in living cells are caused chemically. When an active presynaptic cell releases neurotransmitters into the synapse, some of them bind to receptors on the postsynaptic cell. This depolarizing current causes an increase in membrane potential, the EPSP.
What is the Sepsc frequency?
The frequency of sEPSCs was also quite variable, ranging from 0.2 to 5 Hz. sEPSCs were equivalent to miniature EPSCs recorded in the presence of tetrodotoxin, and both sEPSCs and emEPSCs were CNQX-sensitive.
Why chloride entering the postsynaptic neuron causes an inhibitory postsynaptic potential?
This is because, if the neurotransmitter released into the synaptic cleft causes an increase in the permeability of the postsynaptic membrane to chloride ions by binding to ligand-gated chloride ion channels and causing them to open, then chloride ions, which are in greater concentration in the synaptic cleft, diffuse …
What are EPSPs and IPSPs and what is their function?
An EPSP is received when an excitatory presynaptic cell, connected to the dendrite, fires an action potential. An inhibitory postsynaptic potentials (IPSP) is a temporary hyperpolarization of postsynaptic membrane caused by the flow of negatively charged ions into the postsynaptic cell.
What is the difference between an inhibitory and an excitatory postsynaptic potential?
Postsynaptic potentials are graded changes in the membrane potential of a postsynaptic synapse. Excitatory postsynaptic potentials (EPSP) bring the neuron’s potential closer to its firing threshold. Inhibitory postsynaptic potentials (IPSP) change the charge across the membrane to be further from the firing threshold.
Which connections have the first EPSP most potentiated during frequency modulation?
Connections at which the first EPSP was most potentiated tended to be those which showed the most depression of EPSP amplitude during the high-frequency portion of the train. Thus, at some connections, modulation of EPSP amplitude during the frequency-modulated train was much greater than at other connections.
What changes the amplitude of mEPSC?
Thank you all very much for your answers! Any of the factors you mentioned could change mEPSC amplitude, namely, less neurotransmitter content per quanta (per presynaptic vesicle), fewer postsynaptic receptors, or a change in the type of receptors at postsynaptic sites (i.e., a change in the single channel conductance of ligand gated receptors).
How does EPSP amplitude change during high-frequency trains?
The initial EPSP was generally potentiated, and EPSPs in the high-frequency (greater than 200 Hz) middle portion of the train were generally reduced in amplitude. Connections at which the first EPSP was most potentiated tended to be those which showed the most depression of EPSP amplitude during the high-frequency portion of the train.
Do chronic ap5-treated neurons produce different mEPSC amplitudes?
The mEPSC amplitudes recorded from chronic AP5-treated neurons (25.5 ± 0.3 pA; n = 30 neurons) were significantly larger than that recorded from control neurons (21.6 ± 0.2 pA; n = 30 neurons, p < 0.05), whereas the frequency of mEPSCs was not changed.