Synaptic plasticity

1. Mechanic or not—-main question is what are the cellular and mol. Mechanism of memory formation in the hippocampus

   1. How it underlies learning and memeory

2. Model of plasticity

   1. Study memory even its not localized —how brain store memory and a new field came along (local of hippo, the hippo field develop)

   2. Study plasticity —how neuron respond when stimulated, how long the plasticity occurs—essential for learning and memory

   3. The path

      1. Enthohinal cortex (Perforant path)—→ Dentate (Mossy fibers) —-CA3 pyramidal cells (Schaffer) —→ CA1 pyramidal cells

      2. DOES IT VECOME PLATIC AND HOW LONG?

3. LONG-term potentiation

   1. Input path to hippo stimulated (SE-stimulating electrode)—> RE by Grabuke cells to stimuli axons coming and recor—-endure plasticity?

   2. WEAK STIMULATION (WS) (Engel for next neuron to fire) vs SE (fire AP, calcium in)

      1. Weak —weak response by neurons (pp)

      2. Strong—strong response by neurons [To Perforant path (PP)

      3. Weak again after strong—→assume small, small response but after SW, a bigger response in GC in Dentate gurus —circuit has changed when SS is given to a SW neuron, strengthen response

      4. Potentiated when stimuli stimulated strong —lasted a while that supported learning and memory

      5. Other BD —synapse weaking by stimulation WS over time

   3. LTP—increase of the strength of synaptic response as a result of stimulation

      1. In vivo—in the living (whole animal)

      2. In vitro—within the glass (brain slice).

4. LTP and the Idealized NEURON

   1. Dendrites—→nucleous + cell body —> axon hillock —> axon —> axon terminal

   2. AXON terminal with pre and post synaptic neurons

   3. A.xon terminal that will terminate in cell body or in dentrites

   4. Dendritic spines—-bumps where com of pre and post happens since there where the synapses are —-synapse chemical in nature with a gap—excitatory or inhibitory PP current that changes the excitiability of PC (GLU —T, GAA—inhibitory current in PSC)

5. LTP. In a graph —a reading (-70 mV b/c inside is negative hen the outside which is more positive)

   1. Resting Potnetial—-70

   2. Depolarization—-less negative ]

   3. Hyperpolarization—+ positive —GABBA RECEPTORS

   4. -30 AP

   5. UNDERLINE CONNECTION

      1. CA3–stimulat —-SS—CA1

      2. whenn first stimulated, noice but later a response of PSC —a bit longer b/c its a synaptic -chemical mechanism —-Stimuli input —-poaitcve

      3. EPSP—excitatory PSP—LTP—-depolarization (inside, positive changes) —→ GRAPH for LTP y= ESPS field, x-axis—>test stimulus