Behavioral Neuroscience M2

Structure & Function of Cells in the Nervous System

• Overview of the cellular organization in the nervous system.

• Connection between structure and function in neural cells.

Physical Scales in the Nervous System

• Examination of anatomical scales in nervous systems of different species.

• "Anthropopithecus troglodyle" references specific brain structures.

• Discussion of larger brain systems and their mapping.

• Introduction of circuits within the nervous system, focusing on neurons and synapses.

Physical Scales in the Nervous System

• Further elaboration on the structural aspects and variations.

• Importance of understanding these scales for neuroscience research.

Main Topics for This Chapter

• Cells of the Nervous System: Types and roles.

• Communication Within a Neuron: Mechanisms of signal transduction.

• Communication Between Neurons: Synaptic transmission and neural networks.

Divisions of the Nervous System

• Central Nervous System (CNS): Brain and spinal cord.

• Peripheral Nervous System (PNS): All other nerves outside of the CNS.

Nerves Relay Information

• Definition of a nerve as a bundle of axons.

• Structure of nerves in PNS and CNS.

• Example: Sciatic nerve as a tract of axons in CNS.

Neurons

• Neurons as fundamental units of behavior, encompassing:

  • Thinking

  • Feeling

  • Reasoning

  • Perceiving

  • Remembering

Types of Neurons

• Sensory Neurons: Transmit sensory information.

• Interneurons: Process information within the CNS.

• Motor Neurons: Relay signals to muscles.

Neurons Are (Nerve) Cells

• Anatomy of a typical neuron including:

  • Lysosome

  • Ribosomes

  • Cilia

  • Cel membrane

  • Others like Golgi apparatus and mitochondria.

Parts of a Neuron

• Key components of a neuron:

  • Dendrites: Receive signals.

  • Soma (cell body): Contains nucleus.

  • Myelin Sheath: Insulates axon to enhance signal transmission.

Architecture of Neurons

• Detail on synaptic structures:

  • Synapses on soma

  • Myelin sheath

  • Terminal buttons and dendritic connections.

Axoplasmic Transport

• Overview of axonal transport mechanisms:

  • Anterograde Transport: Movement down the axon.

  • Retrograde Transport: Movement toward the cell body.

  • Role of microtubules in transport systems.

Supporting Cells in the CNS

• Glial Cells: Supporting cells including:

  • Astrocytes: Nourish neurons.

  • Oligodendrocytes: Myelin production.

  • Microglia: Immune defense in the CNS.

Microglia

• Discussion on Microglia's role in the nervous system as immune regulators.

Supporting Cells in the PNS

• Glial Cells: Focus on Schwann cells.

  • Role in myelination of peripheral nerves.

The Blood-Brain Barrier

• Description of the blood-brain barrier structure and its function.

• Importance of selective permeability for maintaining homeostasis in the brain.

Review Topics

• Comparison of central vs peripheral nervous systems.

• Basic structures and functions of neurons and supporting cells.

• Importance of the blood-brain barrier.

Neurons as Communication Agents

• Neurons communicate with:

  • Other neurons

  • Voluntary muscles

  • Involuntary muscles

  • Sense organs

  • Glands

Example of Withdrawal Reflex

• The process that occurs during the withdrawal reflex:

  • Sensory neuron detects pain.

  • Interneuron excites the motor neuron for muscle contraction.

How Communication Within a Neuron Works

• Action Potentials: Mechanism of signal propagation along axons.

Electrical Potentials of Cell Membranes

• Understanding resting potential structures and their functions:

  • Neurons are bioelectric systems with resting potentials.

Why Resting Potential is -70 mV

• Factors influencing resting potential:

  • Diffusion

  • Electrostatic pressure

  • Sodium-potassium pump mechanism.

The Rate Law

• Concept of neuronal firing rates:

  • Relationship between stimulus strength and action potential frequency.

Conduction of Action Potentials in Unmyelinated Axon

• Description of the sequence of ion movements during action potentials.

Conduction of Action Potentials in Myelinated Axon

• Saltatory Conduction: Mechanism of action potential propagation along myelinated axons.

Communication Between Neurons

• Synaptic Transmission: Process of communication at synapses.

Synapse Structures

• Layout of synaptic components:

  • Presynaptic and postsynaptic neurons.

Postsynaptic Potentials

• Types of postsynaptic potentials:

  • EPSP: Excitatory postsynaptic potential.

  • IPSP: Inhibitory postsynaptic potential.

Termination of PSP

• Processes that mitigate postsynaptic potentials:

  • Reuptake and enzymatic deactivation of neurotransmitters.

Regulating Synaptic Activity

• Mechanisms involved in regulating synaptic events:

  • Inactivation of neurotransmitters.

  • Changes in receptor sensitivity.

Neural Integration

• Mechanisms combining EPSPs and IPSPs to regulate neuron firing.