Neurochemistry

• Synaptic transmission

  • The process of transmitting messages from neuron to neuron across a tiny gap between neurons called a synapse.
• Synaptic Tranmission

  • Along a nerve cell, impulse is electrical. At the gap it is chemical.
  • The neurotransmitters that continue the message are released at the presynaptic membraine into the synapse.
  • They are released from tiny sacs called synaptic vesicles
  • They are taken up from receptors on the receiving neuron and converted into electrical impulses to continue transmission
  • There are receptor sites for specific types of neurotransmitters. The process of synapse is like a lock and key system, as only certain neurotransmitters can unlock a message channel in posy synaptic neurons
• Excitation and inhibition

  • whether a neuron fires or not depends on the sum of excitatory and inhibitory neurotransmitters
  • an e.g. of inhibitory is GABA which has a calming effect on the nervous system and makes the neuron less likely to fire
  • an e.g. of excitatory is adrenaline which makes the neuron more likely to fire
  • excitatory accelerates firing and inhibitory decreases firing
• Synaptic pruning

  • when different synaptic connections that are not as frequently used are deleted and new ones are formed