Chapter 2 brain and behavior

A process by which individuals or groups are systematically deprived of their rights, dignity, or status, often resulting in significant psychological and social consequences.

Abasement

The act of diminishing or reducing the intensity, amount, or degree of something, often used in contexts such as environmental phenomena or emotional states.

Abatement

The formal relinquishment of a throne or high office, typically occurring in the context of political upheaval or personal decision, leading to a transfer of power.

Abdication

The unlawful act of seizing and carrying away a person by force or fraud, often associated with criminal activities and legal ramifications.

Abduction

An occurrence or situation that deviates from the expected or typical pattern, often analyzed in statistical contexts to understand anomalies.

Aberration

To assist or facilitate an action, particularly in a legal or moral context, where one party supports another in the commission of a crime or unethical act.

Abetting

Synapse

A junction between neurons where chemical communication occurs, a term coined by Charles Scott Sherrington in 1906.

Excitatory Postsynaptic Potential (EPSP)

A graded depolarization of the postsynaptic membrane that decays over time and space, contributing to the summation of signals in neurons.

Presynaptic Neuron

The neuron that sends the signal across the synapse during synaptic transmission.

Postsynaptic Neuron

The neuron that receives the signal at the synapse.

Temporal Summation

The process by which repeated stimuli over a short period can produce a stronger postsynaptic response, allowing for the generation of a nerve impulse.

Spatial Summation

The cumulative effect of synaptic inputs from multiple locations that can trigger a nerve impulse when individual stimuli are insufficient.

Inhibitory Synapses

Synapses that decrease the likelihood of the postsynaptic neuron firing by causing hyperpolarization.

Inhibitory Postsynaptic Potential (IPSP)

A temporary hyperpolarization of the postsynaptic membrane that serves as a brake to suppress excitation.

Chemical Communication

The process by which neurons transmit signals through the release of neurotransmitters rather than electrical impulses.

Neurotransmitter

Chemicals synthesized by neurons that transmit signals across the synapse by binding to receptors on the postsynaptic neuron.

Ionotropic Effects

Rapid effects that occur when neurotransmitters bind to receptors and immediately open ion channels, leading to quick changes in the postsynaptic cell's membrane potential.

Metabotropic Effects

Slower and longer-lasting effects initiated by neurotransmitters binding to receptors that activate metabolic pathways within the postsynaptic neuron.

Second Messenger Systems

Intracellular signaling pathways activated by neurotransmitter binding that lead to prolonged changes in cellular activity.

Acetylcholine

A neurotransmitter synthesized from choline, crucial for muscle activation and various brain functions.

Catecholamines

A group of neurotransmitters that includes epinephrine, norepinephrine, and dopamine, characterized by a catechol group and an amine group.

Glutamate

The primary excitatory neurotransmitter in the brain, playing a key role in synaptic plasticity and cognitive functions.

GABA (Gamma-Aminobutyric Acid)

The main inhibitory neurotransmitter in the brain, crucial for regulating neuronal excitability and preventing overactivity.

Reflex Arc

A neural pathway that controls a reflex action, involving sensory neurons, interneurons, and motor neurons.

Interneuron

A type of neuron that connects sensory and motor pathways, often involved in reflex actions.

Neurotransmitter Recycling

The process by which neurotransmitters are reabsorbed by the presynaptic neuron after their release, allowing for reuse in future synaptic transmissions.

Synaptic Activation

The process that occurs when neurotransmitters bind to receptors on the postsynaptic neuron, leading to changes in its membrane potential.

Metabotropic synapses

Utilize various neurotransmitters such as dopamine, norepinephrine, serotonin, glutamate, and GABA, influencing a range of physiological processes.

Metabotropic receptor activation

Involves neurotransmitter binding that induces a conformational change in the receptor protein, initiating intracellular signaling cascades.

G-Proteins

Molecular switches that, when activated by GTP, increase the concentration of second messengers, facilitating communication within the neuron.

Hallucinogenic drugs

Substances that mimic serotonin's structure, such as LSD, and activate serotonin type 2A receptors, leading to altered perception.

Opiate drugs

Bind to specific receptors in the brain, mimicking endorphins, and are involved in pain relief and reward pathways.

Neurotransmitter reuptake

The process by which presynaptic neurons reclaim neurotransmitters from the synaptic cleft for reuse, primarily facilitated by transporter proteins.

Inactivation of neurotransmitters

Involves enzymatic breakdown of neurotransmitters, such as acetylcholine being hydrolyzed by acetylcholinesterase, preventing prolonged signaling.

Stimulant drugs

Substances like amphetamine and cocaine that enhance dopamine release, impacting mood and attention by stimulating dopaminergic synapses.

Negative feedback mechanisms

Regulatory processes involving autoreceptors and postsynaptic feedback that inhibit further neurotransmitter release to maintain homeostasis.

Cannabinoids

Active components in marijuana that bind to anandamide and 2-AG receptors, modulating neurotransmitter release and often reducing anxiety.

Electrical synapses

Specialized synapses that allow direct electrical communication between neurons via gap junctions, facilitating rapid signal transmission.

Hormones

Chemical messengers secreted by glands that travel through the bloodstream to regulate various physiological processes across different organs.

Pituitary gland

A master endocrine gland connected to the hypothalamus, responsible for releasing hormones that control other endocrine glands and numerous bodily functions.

Anterior pituitary

Composed of glandular tissue, it secretes hormones regulated by hypothalamic releasing and inhibiting hormones.

Posterior pituitary

Contains neural tissue and releases hormones like oxytocin and vasopressin, produced in the hypothalamus, in response to neural signals.

Negative feedback in hormone regulation

A control mechanism where the output of a system inhibits its own production, maintaining hormone levels within a physiological range.

Charles Sherrington's contributions

Utilized behavioral observations to deduce synaptic properties, including the roles of excitatory and inhibitory postsynaptic potentials in neural communication.

EPSPs and IPSPs

Excitatory and inhibitory postsynaptic potentials that contribute to the summation of signals at the synapse, influencing neuronal firing patterns.

Ionotropic receptors

Receptors that mediate fast synaptic transmission through direct ion channel opening upon neurotransmitter binding.

Metabotropic receptors

Receptors that initiate slower, longer-lasting effects through G-protein coupled mechanisms and second messenger pathways.

Drug effects on behavior

Various substances alter behavior by interacting with neurotransmitter systems at synapses, impacting mood, perception, and cognition.

Common hormones and their effects

Hormones such as cortisol, adrenaline, and insulin play crucial roles in stress response, metabolism, and energy regulation.