work-storage-byTopic-neuroscience-quals-Q1slides

\documentclass{seminar} \usepackage{colordvi} \begin{document}

Types of synaptic plasticity in the neocortex

\begin{center}\emph{What is the synaptic basis of plasticity in neocortex}\end{center}

Three possible interpretations of my question:


Contents:

\begin{itemize} \item Short term plasticity \begin{itemize} \item Depression \item Facilitation \item Augmentation and PTP \end{itemize} \item Synaptic scaling \item Long term plasticity \begin{itemize} \item STDP \item Different STDP rules \item theta burst induced LTP \item pairing protocol LTP \item LFS-LTD \item Synaptic redistribution \end{itemize} \end{itemize}


Short term synaptic depression

\includegraphics[scale=.7]{depression.eps}

\emph{EPSCs during 50 hz train in PFC, layers III$\to$V }

\bigskip

Mechanisms \RawSienna{\begin{scriptsize}(by analogy with other areas)\end{scriptsize}}


Facilitation

\bigskip

Mechanisms \RawSienna{\begin{scriptsize}(by analogy with other areas)\end{scriptsize}}


Depression vs. facilitation

In neocortex, usually, but not always, depression wins. Example:

\includegraphics[scale=.7]{depressionVsFacilitation.eps}

\emph{2nd fPSP and 15th fPSPs in PFC as a function of stimulation frequency, layers III$\to$V }

seemingly longer decay time constant of depression


Augmentation and PTP

\includegraphics[scale=.7]{augmentation.eps}

\emph{EPSCs in PFC after a 15 stimulus, 50hz tetanus, layers III$\to$V }


Augmentation and PTP cont'd

Mechanisms \RawSienna{\begin{scriptsize}(by analogy with other areas)\end{scriptsize}}


Similar to facilitation: presynaptic, increase in \# of quanta released by a presynaptic spike, residual Ca$^{2+}$ hypothesis


Synaptic scaling

\includegraphics[scale=.8]{synapticScaling.eps}

\emph{cultured pyramidal neurons from visual cortex}


Synaptic scaling cont'd

Mechanisms


STDP


\includegraphics[scale=.6]{stdpRules.eps} \textbf{STDP cont'd: Different STDP rules}


STDP cont'd: Different STDP rules

\includegraphics[scale=.6]{rateTimingCurves.eps}


STDP cont'd: Mechanisms

\includegraphics[scale=.6]{dendriticNaChannels.eps}


STDP cont'd:

Mechanisms

calcium level $\to$ sign of plasticity? Or where the calcium enters important, too?

\includegraphics[scale=.6]{calciumLevelMystery.eps}


STDP cont'd:

Mechanisms

STD-LTP


STDP cont'd:

Mechanisms

STD-LTD


theta-burst LTP

10 bursts of 10 pulses at 100hz bursts, 15 secs in between bursts

\bigskip

Mechanisms


pairing protocol LTP

pair EPSP with postsynaptic depolarization

\bigskip

Mechanisms


LFS-LTD

1 hz, 900 sweeps

\bigskip

Mechanisms


Synaptic redistribution

\bigskip

Mechanisms

Hypothesis: potentiation via increase in probability of release (presynaptic), but depression from more depletion of readily releasable pool


Bibliography

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