Neurological Basis of Behavior: Nervous System, Learning, and Social Networks

What is the role of sensory receptors in adaptive behavior?

They detect stimuli that the CNS evaluates to determine an appropriate response.

What does the Central Nervous System (CNS) consist of?

The brain and spinal cord in vertebrates; brain and nerve cord in invertebrates.

What is the Peripheral Nervous System (PNS)?

All aspects of the nervous system other than the CNS, divided into sensory and motor divisions.

What is a neuron?

The anatomical term for a nerve cell, modified to receive and distribute information.

What are the basic parts of a neuron?

Cell body (perikaryon), dendrites, and axons.

What is the function of dendrites?

They are branching extensions of the cell that are usually receptive in nature.

What is the function of axons?

Typically singular extensions that are distributive in nature, often coated with myelin.

What is myelin and its function?

An insulating coating on axons that allows for faster transmission of information, produced by glial cells.

What are the two types of glial cells that produce myelin?

Oligodendrocytes in the CNS and Schwann cells in the PNS.

What are the three functional classes of neurons?

Sensory (afferent) neurons, motor (efferent) neurons, and interneurons.

What is an action potential?

An electrochemical signal conducted along an axon due to the uneven exchange of sodium and potassium cations.

What does the 'all-or-none-hypothesis' state about action potentials?

They fire at 100% or not at all; variations in stimulus intensity are due to firing rates and neuron response numbers.

What is a synapse?

The junction where neurons exchange information, consisting of a synaptic cleft between a presynaptic axon and a postsynaptic dendrite.

What are neurotransmitters?

Chemical signals released in a chemical synapse that propagate an impulse in the postsynaptic neuron.

What is the difference between chemical and electrical synapses?

Chemical synapses involve neurotransmitter release, while electrical synapses allow direct electrical impulse transfer.

How do animals process sensory stimuli efficiently?

Their sensory systems must be selective to focus on important stimuli relevant to their environment and fitness.

Why are many special sense organs paired in animals?

To allow for localization of the source of a stimulus, such as scent or sound.

What is negative phonotaxis?

The behavior where crickets fly away from the echolocation calls of bats.

What is the response time for crickets to evade bats?

They can steer away from the sound source within 40-80 milliseconds.

How many receptors do crickets have in their foreleg ears?

70 receptors, allowing them to detect a range of echolocating calls.

What is the role of the AN2 interneuron in crickets?

It exhibits rapid responses to echolocating call stimuli, crucial for evasion behavior.

What are the two ascending interneurons in the 'Teleogryllus' cricket responsible for?

One carries information about cricket song (around 5 kHz) and the other responds to ultrasound and high frequencies (15-100 kHz).

What is the significance of the INT-1 interneuron in crickets?

It is necessary and sufficient for initiating negative phonotaxis in response to ultrasound.

What happens to crickets that are decapitated in terms of evasion response?

They can still fly but show no avoidance response behaviors, indicating the brain's necessity for this response.

What correlates with behavioral changes in animals?

Changes in the brain.

What is required for true learning to occur?

The formation of a memory.

How are memories formed in the brain?

Through the strengthening of synapses.

What changes can occur at the synapse to form memories?

Changes in neurotransmitter production, receptor numbers, synapse numbers, and growth of new neurons.

What are the three types of memories?

Short Term, Intermediate Term, and Long Term Memories.

How long can Short Term Memories be retrieved after learning?

For minutes, hours, or a day.

What is the retrieval duration for Intermediate Term Memories?

One or more days after the learning experience.

How long can Long Term Memories be retrieved?

For weeks, months, or even years.

What is the Aplysia californica known for in studies of learning?

Its gill and siphon withdrawal reflex.

What is habituation in the context of nonassociative learning?

A progressive decrease in response to a repeatedly presented stimulus.

What is sensitization?

An increase in response due to the presentation of a novel, often noxious, stimulus.

What does dishabituation refer to?

The restoration of a habituated response when a new stimulus is presented.

Why is the sea hare an excellent model for studying learning?

It has a simple nervous system with only 20,000 large neurons.

What happens to neurotransmitter release during habituation?

It decreases due to fewer synaptic vesicles being recruited.

What is Long Term Potentiation (LTP)?

A stable and long-lasting enhancement in signal transmission between neurons due to strong stimulation.

What is the opposite of Long Term Potentiation?

Long Term Depression (LTD).

What is Long Term Depression (LTD)?

A lasting decrease in responsiveness of postsynaptic neurons after slow repetition of stimuli.

What is synaptic remodeling?

The refinement of synaptic connections during memory formation.

What is neurogenesis?

The creation of new neurons.

How has the understanding of neurogenesis changed over time?

It was once thought to stop at birth, but now is known to play a role in memory formation.

What role does neurogenesis play in Alzheimer's disease?

It may be inhibited in Alzheimer's disease.

How do zebra finches learn their songs?

By listening to and memorizing the songs of their parent or adult tutor.

What are the two phases of song learning in young male zebra finches?

Memorization and practice.

How many times might a zebra finch need to practice singing to accurately imitate its tutor's song?

As many as 100,000 times in a 45-day period.

Which universities conducted research on zebra finch vocal learning?

Duke and Harvard universities.

What technology was used in the study to control nerve cell activity?

Optogenetics.

What did the study reveal about the song pre-motor region in a zebra finch's brain?

It controls the execution of learned vocal sequences and helps encode information while listening to the tutor.

What is the traditional view of how humans learn behaviors like language and music?

By listening to a model and then emulating it through intensive practice.

What role does the brain region essential for motor control of song play in auditory learning?

It is essential for both motor control and auditory learning of the tutor's song.

Who was the first researcher to propose the idea of Social Behavior Networks (SBNs)?

Sarah Newman.

What did Sarah Newman determine about sexual behavior in mammals?

It results from many brain nuclei acting in concert, influenced by external stimuli and hormonal history.

Name one of the six brain regions that control mammalian social behavior according to Sarah Newman.

The amygdala.

What is the function of the ventromedial hypothalamus?

It is involved in feeding, fear, thermoregulation, and sexual activity.

What is the significance of sex hormone receptors in the context of social behavior?

They are necessary for sexual differentiation and the coordination of social behavior.

How do the six regions of the social behavior network interact?

They exchange information in both directions.

What is the motor response in the context of the central nervous system?

Motor information traveling from the CNS to an effector organ causing a response to a stimulus.

What are effector organs in the context of motor responses?

Muscles or glands.

What is a sensory reflex?

A response initiated by sensory neurons that can activate motor neurons.

What is a Central Pattern Generator (CPG)?

A neuron or neural network that produces rhythmic motor outputs without requiring sensory feedback.

What are the requirements for a CPG to be classified as a rhythmic generator?

It must have two or more processes that interact, causing the system to return to its starting condition.

Give an example of a function that CPGs can serve in animals.

Movement, breathing, rhythm generation, and other oscillatory functions.

What is the role of motor commands in relation to sensory input?

They send impulses from the CNS to effector organs based on sensory input.

How do interneurons from the brain influence CPG activity?

They initiate and modulate activity in a CPG.

What is the significance of the study on zebra finches for understanding human behavior?

It suggests parallels in how both species learn complex behaviors through imitation and practice.

What is the role of the medial amygdala in social behavior?

It is part of the brain regions involved in various social behaviors, including aggression and bonding.

What is the relationship between social behavior networks and other vertebrates?

SBNs have been mapped in mammals and are believed to exist in other vertebrates, including birds and bony fish.

How do the nodes of the social behavior network in birds compare to those in mammals?

They are reciprocally connected, contain sex steroid hormone receptors, and are involved in multiple forms of social behavior.

What does the study of zebra finch vocal learning contribute to neuroscience?

It helps identify brain circuits necessary for learning and imitation, relevant to understanding learning in other species.