Alright, we can start talking about neurotransmitters! The first one up is the most abundant in the brain (chemical structure pictured above). It’s largely excitatory and generally acts on ion channels. Have you guessed it yet? It’s glutamate!
Glutamate is implicated in synaptic plasticity and long-term potentiation. Two of the main receptors it acts upon are the AMPA and NMDA receptors. AMPA receptors let Na+ into the neuron, depolarizing it and potentially causing an action potential. NMDA receptors, which are voltage-dependent (they have a Magnesium block that only moves when the inside of the cell is depolarized enough) AND ligand-gated (they also need glutamate to open), let in both Na+ AND Ca2+ (calcium)- they are less ion specific. This calcium seems to have effects for long-term potentiation (LTP- which is the core of learning and memory, whereby the same activation will make a cell more likely to fire after LTP… so we increase the EPSP after LTP, thus, making it closer to the threshold for an action potential - see here).
The calcium that enters essentially (through downstream effectors) causes more AMPA receptors to be inserted into the postsynaptic membrane. A process sometimes called “AMPAfication” (amplification- ampafication- get it?). This means that when glutamate is released the next time by the presynaptic neuron, more AMPA receptors will open and more sodium will enter the postsynaptic neuron, meaning there will be more depolarization!
Out for a walk trying to find a bouldering gym, failure is met with a surprising discovery of an abandoned climbing wall and some seriously shady security. Oh the river is my walk to class!
Breakin’ good
Acid rain
