Cells electrical action start small as electro-impulses generated at AXON HILLOCK, but once it reaches axon terminal the neuron’s terminal button can pass its chemical message across the synaptic gap.
Each Neuron is responsible for producing a certain NT and when the action potential reaches the axon terminal, calcium channels open in the pre-synaptic neuron and flood the terminal button with calcium ions. Vesicles containing NT will then be released & travel down the outer membrane of pre-synaptic allowing NT to be released into synaptic cleft. Once there they are picked up by receptor sites on the post-synaptic Neuron which is designed for that NT it will have an inhibitory (close ion channel) or excitery (open ion channels) allowing for NT to pass on ion channel. NT left in the cleft will be destroyed by enzymes or re-uptaken by pre-synaptic neuron.
Strengths | Weaknesses |
Jovanovic – studied women with pre-mensural dysphoric disorder (PMDD) scanning before & after ovulation finding women had low levels of serotonin linked to depression – women with PMDD show differences in synaptic receptors suggesting synaptic transmissions relates to mood
High V – in animal studies they have strict control over EV used during & prior to the research – cause & effect relation can be established Scientific – brain scanning is increasingly used which gathers objective data which can only be interpreted in a strict way – reduces researcher bias & more creditable to research. |
Jovanovic – low gen – only used women with pre-mensural dysphoric disorder – cannot generalise to all women or men at all.
Allen & steven – found synaptic transmissions involving hippocampal neurons to be very unreliable as half NT leaving pro-synaptic arrive at post-synaptic – Nt may not work reliably & regularly Animal studies – responsible for most synaptic transmission where lesions can be made – difficult to generalise to humans as we have different emotional functioning & consciousness with higher order thinking. |