I behavior analysis I in a natural environment I in the laboratory I cells, synapses & circuits I basic properties of nerve cells I synaptic transmission I neuronal architecture & behavior I relating nerve cells to behavior I summary #04: CELLS, SYNAPSES & CIRCUITS

I behavior analysis I in a natural environment I in the laboratory I cells, synapses & circuits I basic properties of nerve cells I synaptic transmission I neuronal architecture & behavior I relating nerve cells to behavior I summary #04: CELLS, SYNAPSES & CIRCUITS

I behavior analysis I in a natural environment I in the laboratory I cells, synapses & circuits I basic properties of nerve cells I synaptic transmission I neuronal architecture & behavior I relating nerve cells to behavior I summary #04: CELLS, SYNAPSES & CIRCUITS

I behavior  circuits of interacting neurons, 3 types: SENSORY INPUT CENTRAL PROCESSING MOTOR OUTPUT BEHAVIOR NEURONAL ARCHITECTURE OF BEHAVIOR

I behavior  circuits of interacting neurons, 3 types: I sensory neurons... signal input I specialized receptor cells I convert features of environment  neural signals I interneurons... central processing I motor neurons... motor output (behavior) I drive muscle neuromuscular junction I generate  excitatory junctional potentials (EJPs) NEURONAL ARCHITECTURE OF BEHAVIOR

I electrical recordings: I electrode type I position ~ cells I extracellular   V,  I intracellular  mV,  I advantages & disadvantages p.24, fig.1.10 NEURONAL ARCHITECTURE OF BEHAVIOR

 extracellular electrode I motor neurons I “unit” activity (>1) I ~ current flow in extracellular space p.24, fig.1.10 NEURONAL ARCHITECTURE OF BEHAVIOR

 intracellular electrode I single motor neuron p.24, fig.1.10 NEURONAL ARCHITECTURE OF BEHAVIOR

 extracellular electrode I records propagation of action potentials along axons p.24, fig.1.10 NEURONAL ARCHITECTURE OF BEHAVIOR

 intracellular electrode I muscle fiber I EJPs  signals... I motor neuron  I others p.24, fig.1.10 NEURONAL ARCHITECTURE OF BEHAVIOR

 extracellular electrode I electromyogram (EMG) I whole muscle activity p.24, fig.1.10 NEURONAL ARCHITECTURE OF BEHAVIOR

I behavior  circuits... simple ones (in mammals) I e.g., human knee jerk reflex... I tap knee below patella I  stretches receptors in quads (muscle spindles) I activates sensory neurons (Ia) I synapse  motor neurons (  ) I  contraction of quads p.25, fig.1.11 NEURONAL ARCHITECTURE OF BEHAVIOR

I behavior  circuits... simple ones (in mammals) I e.g., human knee jerk reflex... I simple ? I sensory-motor ? I monosynaptic ? I no, other neurons involved p.25, fig.1.11 NEURONAL ARCHITECTURE OF BEHAVIOR

I circuit complexity I e.g., primate visual cortex I boxes = assemblies of I 10 3 s of neurons I 10 6 s of synapses I 2 main pathways I V1  PG... object location I V1  TE... visual form p.25, fig.1.11 NEURONAL ARCHITECTURE OF BEHAVIOR

I circuit complexity I e.g., primate visual cortex I Q: how to study cellular properties of neurons among such complexity ? I A: chose: I accessible behavior I in model organism providing special advantages p.25, fig.1.11 NEURONAL ARCHITECTURE OF BEHAVIOR

I advantages & disadvantages I interesting... it is ALL interesting (not only ~ humans) I maintenance, availability & access to sufficient #s I model system... biology & tools available I behavior I anatomy / physiology I cell biology I pharmacology I genetics / genomics / proteomics NEURONAL ARCHITECTURE OF BEHAVIOR

I advantages & disadvantages I 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) NEURONAL ARCHITECTURE OF BEHAVIOR

I advantages & disadvantages I 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 NEURONAL ARCHITECTURE OF BEHAVIOR

I behavior analysis I in a natural environment I in the laboratory I cells, synapses & circuits I basic properties of nerve cells I synaptic transmission I neuronal architecture & behavior I relating nerve cells to behavior I summary #04: CELLS, SYNAPSES & CIRCUITS

I investigating how neurons  behavior I e.g., crayfish response to tail tactile stimulus I record lateral giant interneuron (LGI) I correlation (A): always stimulus  behavior ?... p.27, fig.1.12 RELATING NERVE CELLS TO BEHAVIOR

I investigating how neurons  behavior I e.g., crayfish response to tail tactile stimulus I record lateral giant interneuron (LGI) I correlation (A): always stimulus  behavior ?... I sufficient (B): trigger LGI alone  response ?... p.27, fig.1.12 RELATING NERVE CELLS TO BEHAVIOR

I investigating how neurons  behavior I e.g., crayfish response to tail tactile stimulus I record lateral giant interneuron (LGI) I correlation (A): always stimulus  behavior ?... I sufficient (B): trigger LGI alone  response ?... I necessary (C): shut off LGI  no response ?... p.27, fig.1.12 RELATING NERVE CELLS TO BEHAVIOR

I investigating how neurons  behavior I e.g., crayfish response to tail tactile stimulus I record lateral giant interneuron (LGI) I correlation (A): always stimulus  behavior ?... I sufficient (B): trigger LGI alone  response ?... I necessary (C): shut off LGI  no response ?... I should always attempt to ask these 3 questions, but I we rarely find this type of simplicity in nature RELATING NERVE CELLS TO BEHAVIOR

I investigating how synapses  behavior I e.g., Drosophila escape response (mutants, pharmacological agents) I inject current across brain RELATING NERVE CELLS TO BEHAVIOR

I investigating how synapses  behavior I e.g., Drosophila escape response (mutants, pharmacological agents) I inject current across brain I measure speed of transmission in down-stream motor neurons I chemical synapses: slow RELATING NERVE CELLS TO BEHAVIOR

I investigating how synapses  behavior I e.g., Drosophila escape response (mutants, pharmacological agents) I inject current across brain I measure speed of transmission in down-stream motor neurons I chemical synapses: slow I electrical synapses: fast (middle leg) escape behavior RELATING NERVE CELLS TO BEHAVIOR

I investigating how restricted neural networks  behavior I e.g., lobster ingestion I food  esophagus  3 chamber stomach: I cardiac sac I gastric mill I pylorus RELATING NERVE CELLS TO BEHAVIOR

I investigating how restricted neural networks  behavior I e.g., lobster ingestion I food  esophagus  3 chamber stomach: I cardiac sac I pylorus (A) I gastric mill (C) } rhythmic p.28, fig.1.13 RELATING NERVE CELLS TO BEHAVIOR

I investigating how restricted neural networks  behavior I e.g., lobster ingestion I stomatogastric ganglia (STG)  rhythm I all 30 neurons known I circuits mapped (B,D) I functions in isolated preparations (A,C) p.28, fig.1.13 RELATING NERVE CELLS TO BEHAVIOR

p.30, fig.1.14 I neural control  behavior in complex organism I e.g., selective attention in monkeys (stimulus choice) I unit recordings in cortex I cellular response to peripheral light (A) RELATING NERVE CELLS TO BEHAVIOR

p.30, fig.1.14 I neural control  behavior in complex organism I e.g., selective attention in monkeys (stimulus choice) I unit recordings in cortex I cellular response to peripheral light (A) I response > if animal pays attention (B) RELATING NERVE CELLS TO BEHAVIOR

p.30, fig.1.14 I neural control  behavior in complex organism I e.g., selective attention in monkeys (stimulus choice) I unit recordings in cortex I cellular response to peripheral light (A) I response > if animal pays attention (B) I response >> if animal  ~ behavior (C) RELATING NERVE CELLS TO BEHAVIOR

I neural control  behavior in complex organism I e.g., selective attention in monkeys (stimulus choice) I  visual system response due to I ~ stimulus I other neural systems  ~ attention (& ~ activity ?) I gain some understanding of mechanism, even at this simple level of analysis RELATING NERVE CELLS TO BEHAVIOR

I behavior analysis I in a natural environment I in the laboratory I cells, synapses & circuits I basic properties of nerve cells I synaptic transmission I neuronal architecture & behavior I relating nerve cells to behavior I summary #04: CELLS, SYNAPSES & CIRCUITS

I behavior... examples discussed: I field studies  ethology I ethograms I FAP, SS, IRM, releasers, interlocking releasers I laboratory studies  associative learning I classical / Pavlovian conditioning, US, CS, UR, CR I operant/instrumental conditioning SUMMARY: INTRODUCTION & TERMS

I nervous system I neurons I channels, resting potentials, action potentials I synapses I chemical, electrical, EPSPs, IPSPs I plasticity, synaptic depression & potentiation, presynaptic inhibition & facilitation I circuits I sensory neurons, interneurons, motor neurons I recording neural activity SUMMARY: INTRODUCTION & TERMS

I relating nerve cells to behavior I neurons  behavior I crayfish tail flip response I synapses  behavior I Drosophila escape response I restricted circuits  behavior I lobster digestion I whole organism  behavior I monkey selective attention SUMMARY: INTRODUCTION & TERMS

I nervous system development and plasticity… I neurogenesis, apoptosis and necrosis I growth I cell adhesion and axon pathfinding I formation, maintenance and plasticity of synapses I organogenesis I general brain and nervous system anatomy… I humans I other vertebrates I invertebrates SUMMARY: WE HAVE NOT DISCUSSED…

I brains are not merely composed of neurons… glia… I oligodendrocytes* and astrocytes (CNS) I Schwann cells (PNS)* I form myelin sheath (vertebrates) I neuron cell structure… general categories… I microfilaments, neurofilaments and microtubules I axon transport I structure and functional details at synapses I ion channel anatomy SUMMARY: WE HAVE NOT DISCUSSED…

I details about signals transmission… I action potentials I frequency coding I signal propagation I myelin function I “types” of signalling I silent, beating, bursting I effects of sustained neural stimulation I changing neuron properties SUMMARY: WE HAVE NOT DISCUSSED…

I measuring currents and channels… electrophysiology… I criteria for ion channel activities I conductance, selectivity, gating, pharmacology I activation, inactivation I whole cell voltage clamp I patch (voltage) clamp I ion channel molecular biology and manipulation I maintenance of ion concentration gradients SUMMARY: WE HAVE NOT DISCUSSED…

I intercellular communication… I gap junctions and neurosecretion I neurotransmitter release I transmitters and hormones I receptors and transduction mechanisms I neuromoduation SUMMARY: WE HAVE NOT DISCUSSED…