The Synapse

Biology of Synaptic Transmission - The Synapse

  • Synaptic vesicles release neurotransmitters into the synaptic cleft
  • Excitatory neurotransmitters initiate action potentials in the adjacent neuron
  • Enables neurons to transmit signals across the synapse
  • Inhibitory neurotransmitters regulate activity in the adjacent neuron and shape neuronal network activity
  • Dysfunction in the processes of synaptic transmission may underlie multiple brain diseases including deficits in memory and cognition

Biology of Synaptic Transmission - Network Activity

Neurons in the brain work together in complex networks. Active networks produce electrical oscillations that are detectable by electroencephalography (EEG) measurements. Different oscillation frequencies have been linked to different neurological activities, such as memory and sleep. In disease states, synaptic dysfunctions impair these network activities, which results in detectable changes in EEG patterns. And these network activities are better conserved between animals and humans than are the corresponding behaviors. At Galenea we believe that by focusing on the underlying neuronal network activity, a far more reliable and predictive approach to CNS drug discovery can be built.

Neural Oscillations are a Window to Network Function

Rhythm Frequency (Hz) State or Function
Delta 0.1 - 3 Slow wave sleep
Theta 3 - 8 REM sleep, meditation, long range synchrony
Alpha 9 - 12 Closed eyes, relaxing, cortical timing (inhibition)
Beta 12 - 30 Alert eyes open
Gamma 30 - 90 Mental activity, attention, manipulation of information
Ripple 100 - 300 Information storage, epilepsy
Fast Ripple 300 - 500 Epilepsy, pathologic