General Bio 115
9/3/14

Concept 49.4

A. During embryonic development
a. Regulated gene expression and signal transduction initiates synapse development on the one hand vs. neutron and synapse, death on the other
b. Helping to shape the NS; establishing connections and networks for life, and the overall CNS organization

B. Neuronal plasticity
a. Brain is dynamic and changeable  connections between neurons can be modified
b. Most remodeling occurs at synapses (the piece between the end of one neuron the beginning of another neuron) -stimulates the brain
c. Changes are activity dependent; connections between synapses must be reinforced to maintain useful info

C. Use it or lose it a. Remodeling or neuronal plasticity is essential for establishments of memories b. Activity dependent; results in addition or loss of synapse: net effect is increased signaling between certain synapses and reduced/loss in others (fig. 49.20a)

c. Multiple synapses active  can strengthen response at all synapses (fig. 49.20b)

Autism Hypothesis- disruption of activity: dependent remodeling at synapses, in early childhood, leads to inability to communicate and socialize

D. Memory a. Short-term memories (STM) stored in hippocampus acquires and holds info ~30 seconds e.g. new telephone #; short retention so released if no longer needed, or sent to long term memory (LTM) for retention b. LTMs are maintained in cerebral cortex; retains information and stores it over lifetime; e.g. telephone #, which can then be returned to the STM if needed.
- Damage to hippocampus (limbic system) leads to inability to distribute new memories to LTM while retention of old memories OK

*Alzheimer’s- loss of STM

D. Goals of workshop; activities founded in neuroscience/cognitive psychology a. improve ability to form memories b. use memories to learn (LTP) and problem solve.

- Transfer from STM to LTM (encoding)  forms a sustained memory which is strengthened by association with already retained memories

- Physiologically completing long-term potentiation

E. Long Term Potentiation (LTP) Fig. 49.21 a. Activity dependent ( memory formation, storage, and learning) b. Results in stable increase in size of postsynaptic potentials at synapse c. “Learner” needs to be active and use information d. Use of information is a sorting process so important info is