behavior analysis in a natural environment in the laboratory cells, synapses & circuits

behavior analysis in a natural environment in the laboratory

cells, synapses & circuits basic properties of nerve cells synaptic transmission neuronal architecture & behavior

relating nerve cells to behavior

summary

#04: CELLS, SYNAPSES & CIRCUITS

summary

behavior circuits of interacting neurons, 3 types:

SENSORY INPUT

CENTRAL PROCESSING

MOTOR OUTPUT

BEHAVIOR

NEURONAL ARCHITECTURE OF BEHAVIOR

behavior circuits of interacting neurons, 3 types:

sensory neurons... signal input specialized receptor cells convert features of environment neural signals

interneurons... central processing

motor neurons... motor output (behavior) drive muscle activity @ neuromuscular junction generate excitatory junctional potentials (EJPs)

electrical recordings:

electrode type

position ~ cells extracellular V, intracellular mV, advantages & disadvantages

p.24, fig.1.10

extracellular electrode

motor neurons

“unit” activity (>1)

~ current flow in extracellular space

p.24, fig.1.10

intracellular electrode

single motor neuron

p.24, fig.1.10

records propagation of action potentials along axons

p.24, fig.1.10

intracellular electrode

muscle fiber

EJPs signals... motor neuron others

p.24, fig.1.10

electromyogram (EMG)

whole muscle activity

p.24, fig.1.10

behavior circuits... simple ones (in mammals)

e.g., human knee jerk reflex...

tap knee below patella

stretches receptors in quads (muscle spindles)

activates sensory neurons (Ia)

synapse motor neurons ()

contraction of quads

p.25, fig.1.11

behavior circuits... simple ones (in mammals)

e.g., human knee jerk reflex...

simple ?

sensory-motor ?

monosynaptic ?

no, other neurons involvedp.25, fig.1.11

circuit complexity

e.g., primate visual cortex

boxes = assemblies of

103 s of neurons

106 s of synapses

2 main pathways V1 PG... object location V1 TE... visual form

p.25, fig.1.11

circuit complexity

e.g., primate visual cortex

Q: how to study cellular properties of neurons among such complexity ?

A: chose:

accessible behavior

in model organism providing special advantages

p.25, fig.1.11

advantages & disadvantages

interesting... it is ALL interesting (not only ~ humans)

maintenance, availability & access to sufficient #s

model system... biology & tools available behavior anatomy / physiology cell biology pharmacology genetics / genomics / proteomics

e.g., C. elegans (nematode)

+ cheap, maintenance, sample sizes, simple behavior, simple anatomy, small simple & well- characterized nervous system, development & cell biology, genetic & pharmacological tools good

– boring behavior, few properties of neuronal assemblies or structures, small neurons (electrophysiology difficult but accessible)

e.g., H. sapiens (humans)

+ interesting behavior, need to knowing how we function (medical), sequenced genome, ~ easy research funding arguments

– prohibitively complex in every respect, moral issues for invasive & experimental study, expensive, inconvenient & uncooperative subjects

summary

investigating how neurons behavior

e.g., crayfish response to tail tactile stimulus

record lateral giant interneuron (LGI) correlation (A): always stimulus behavior ?...

p.27, fig.1.12

RELATING NERVE CELLS TO BEHAVIOR

record lateral giant interneuron (LGI) correlation (A): always stimulus behavior ?... sufficient (B): trigger LGI alone response ?...

p.27, fig.1.12

record lateral giant interneuron (LGI) correlation (A): always stimulus behavior ?... sufficient (B): trigger LGI alone response ?... necessary (C): shut off LGI no response ?...

p.27, fig.1.12

record lateral giant interneuron (LGI) correlation (A): always stimulus behavior ?... sufficient (B): trigger LGI alone response ?... necessary (C): shut off LGI no response ?...

should always attempt to ask these 3 questions, but

we rarely find this type of simplicity in nature

investigating how synapses behavior

e.g., Drosophila escape response (mutants, pharmacological agents)

inject current across brain

measure speed of transmission in down-stream motor neurons

chemical synapses: slow

measure speed of transmission in down-stream motor neurons

chemical synapses: slow electrical synapses: fast (middle leg) escape behavior

investigating how restricted neural networks behavior

e.g., lobster ingestion

food esophagus 3 chamber stomach:

cardiac sac gastric mill pylorus

food esophagus 3 chamber stomach:

cardiac sac pylorus (A) gastric mill (C) } rhythmic

p.28, fig.1.13

stomatogastric ganglia (STG) rhythm

all 30 neurons known circuits mapped (B,D) functions in isolated preparations (A,C)

p.28, fig.1.13

p.30, fig.1.14

neural control behavior in complex organism

e.g., selective attention in monkeys (stimulus choice)

unit recordings in cortex cellular response to peripheral light (A)

p.30, fig.1.14

unit recordings in cortex cellular response to peripheral light (A) response > if animal pays attention (B)

p.30, fig.1.14

unit recordings in cortex cellular response to peripheral light (A) response > if animal pays attention (B) response >> if animal ~ behavior (C)

visual system response due to ~ stimulus other neural systems ~ attention (& ~ activity ?)

gain some understanding of mechanism, even at this simple level of analysis

summary

behavior... examples discussed: field studies ethology

ethograms FAP, SS, IRM, releasers, interlocking releasers

laboratory studies associative learning classical / Pavlovian conditioning, US, CS, UR, CR operant/instrumental conditioning

SUMMARY: INTRODUCTION & TERMS

nervous system neurons

channels, resting potentials, action potentials synapses

chemical, electrical, EPSPs, IPSPs plasticity, synaptic depression & potentiation, presynaptic inhibition & facilitation

circuits sensory neurons, interneurons, motor neurons recording neural activity

relating nerve cells to behavior neurons behavior

crayfish tail flip response synapses behavior

Drosophila escape response restricted circuits behavior

lobster digestion whole organism behavior

monkey selective attention

nervous system development and plasticity… neurogenesis, apoptosis and necrosis growth cell adhesion and axon pathfinding formation, maintenance and plasticity of synapses organogenesis

general brain and nervous system anatomy… humans other vertebrates invertebrates

SUMMARY: WE HAVE NOT DISCUSSED…

brains are not merely composed of neurons… glia… oligodendrocytes* and astrocytes (CNS) Schwann cells (PNS)*

form myelin sheath (vertebrates)

neuron cell structure… general categories… microfilaments, neurofilaments and microtubules axon transport structure and functional details at synapses ion channel anatomy

details about signals transmission… action potentials frequency coding signal propagation myelin function “types” of signalling

silent, beating, bursting effects of sustained neural stimulation changing neuron properties

measuring currents and channels… electrophysiology… criteria for ion channel activities

conductance, selectivity, gating, pharmacology activation, inactivation whole cell voltage clamp patch (voltage) clamp ion channel molecular biology and manipulation maintenance of ion concentration gradients

intercellular communication… gap junctions and neurosecretion neurotransmitter release transmitters and hormones receptors and transduction mechanisms neuromoduation

behavior analysis in a natural environment in the laboratory cells, synapses & circuits

Documents

Transcript of behavior analysis in a natural environment in the laboratory cells, synapses & circuits

© 2013 Pearson Education, Inc. Figure 11.16 Synapses. Axodendritic synapses Dendrites Cell body Axoaxonal synapses Axon Axosomatic synapses Axon Axosomatic.

Lüscher Lab publications - C. Lüscher Synapses, circuits and ...

Neurons& Synapses

Superior olive anatomy-2013 - UConn HealthMNTB principle cells driven by globular bushy cells contralateral Outputs –Bilateral inferior colliculus Synapses – Excitatory glutamate

T Cells’ Immunological Synapses Induce Polarization of.pdf

Storage capacity: consider the neocortex ~20*10^9 cells, 20*10^13 synapses

IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND …IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS, VOL. 4, NO. 3, JUNE 2010 139 Analog VLSI Biophysical Neurons and Synapses With

The Brain. Made up of neurons 23 billion nerve cells and 300 trillion synapses Glial cells – My husband is my glial cell. He takes care of me!!! Whose.

6.5 Neurons and synapses - Peoria Public Schools...6.5.U7 Synapses are junctions between neurons and between neurons and receptor or effector cells. Only chemical synapses are required,

Schools, Skills, and Synapses · Skills Abilities and Outcomes Explanations Critical and Sensitive Periods Circuits Summary The Argument Cognitive abilities are important determinants

Chapter 12 Nervous Tissue Overview of the nervous system Cells of the nervous system Electrophysiology of neurons Synapses Neural integration.

Thin graphene oxide nanoflakes modulate glutamatergic ......2020/03/01 · Thin graphene oxide nanoflakes modulate glutamatergic synapses in the amygdala cultured circuits: Exploiting

SIMULATION OF INTERNAL SHORT CIRCUITS IN ... - UL · PDF fileSimulation of Internal Short Circuits in Lithium-Ion Cells ... safety performance of lithium-ion cells under the conditions

Biosensors and Genetic Circuits Programmable Cells · Biosensors and Genetic Circuits Programmable Cells Technical Journal Club 24.06.2014 ... lacI gene in strains B1 and B2 is based

01 Synapses

Synapses feedback

2021 Application IMPRS for Synapses and Circuits

Whole-Brain Profiling of Cells and Circuits in Mammals by ...

Electrical Synapses

Synaptic Transmission. Electrical & Chemical Synapses Electrical & Chemical Synapses.

Storage capacity: consider the neocortex ~2010^9 cells, 2010^13 synapses