NEUR101 Hormones, Sexual and Reproductive Behavior

Neural communication

Messages travel along fixed channels to precise locations, similar to a telephone system.

Hormonal communication

Messages spread out over the body and are picked up by scattered cells with appropriate receptors, resembling a TV broadcasting system.

Negative feedback loop

A mechanism where the secreted hormone feeds back on the endocrine cells to inhibit further production, similar to a thermostat.

Oxytocin

A hormone released from the pituitary gland that plays a role in behaviors such as the milk letdown reflex.

GnRH (Gonadotropin-releasing hormone)

A hormone that stimulates the release of LH and FSH, which in turn release gonadal hormones.

Androgens

Hormones that promote the development and maintenance of male reproductive organs and secondary sex characteristics.

Estrogens

Hormones that promote the development and maintenance of female reproductive organs and secondary sex characteristics.

Lordosis response

A behavioral response in female mammals that allows for successful mating through body posture.

Coolidge effect

The phenomenon where male animals exhibit a shorter refractory period when presented with a new partner.

Sexual differentiation

The process by which individuals develop either male or female bodies and behaviors.

Aromatization

The process by which testosterone is converted into estradiol in the brain, affecting sexual differentiation and behavior.

5α-reductase deficiency

A genetic mutation where testosterone cannot be converted to dihydrotestosterone (DHT) affecting genital development.

Male sexual dimorphism

Anatomical and behavioral features resulting from sexual selection that enhance reproductive success.

SVN (Spinal nucleus of the bulbocavernosus)

A cluster of motoneurons that support male copulatory behavior and is influenced by androgens.

Behavioral estrus

The period during the ovulatory cycle when females display increased receptivity and proceptivity for mating.

Proceptive behavior

Species-typical behaviors displayed by females to attract males and promote mating.

Cognitive influences on sexual behavior

The ways in which thoughts, dreams, and plans about sex, influenced by the cortex, affect sexual behavior.

Pheromones

Chemicals secreted that influence reproductive behavior by signaling information between individuals.

Sexually dimorphic nucleus of the preoptic area (SDN-POA)

A brain region that is larger in males than females and is organized by perinatal exposure to androgens.

Postcopulatory phase

The stage after copulation where there may be a refractory phase or Coolidge effect influencing future mating.

Endocrine system

A system of glands that release hormones to regulate processes in the body, such as growth, metabolism, and mood.

Hypothalamus

A brain region that links the nervous system to the endocrine system via the pituitary gland.

Pituitary gland

The master gland of the endocrine system that controls other glands and regulates various bodily functions.

LH (Luteinizing hormone)

A hormone produced by the pituitary gland that triggers ovulation in females and testosterone production in males.

FSH (Follicle-stimulating hormone)

A hormone produced by the pituitary gland that controls the development of eggs in females and sperm in males.

Reproductive cycle

The series of physiological changes that occur in females, including the menstrual cycle and estrous cycle.

Territorial behavior

Actions performed by animals to establish and defend a territory, often influenced by hormonal changes.

Mating systems

The patterns of mating behavior observed in species, such as monogamy, polygyny, and polyandry.

Sexual selection

A mode of natural selection where individuals with certain traits are more likely to attract mates and reproduce.

Parental behavior

Actions taken by parents to ensure the survival and welfare of their offspring, often influenced by hormonal factors.

GnRH (Gonadotropin-releasing hormone) relationship with LH and FSH

GnRH stimulates the release of LH and FSH, which are critical hormones in regulating reproductive processes.

Role of the Endocrine System in Mating

The endocrine system regulates mating behaviors and reproductive cycles through the release of hormones.

Impact of Testosterone on Behavior

Testosterone influences male reproductive behaviors and physiological traits, affecting mating success.

Evolutionary significance of Parental Behavior

Parental behavior enhances offspring survival, contributing to evolutionary fitness and species continuation.

Sexual Differentiation in the Brain

Sexual differentiation affects brain structure and function, influencing behaviors attributed to gender.

Environment's Influence on Hormonal Communication

Environmental factors can modify hormonal signals, impacting behaviors like mating and territoriality.

Effect of Androgens on Female Behavior

Androgens can influence female receptivity and mating behaviors through hormonal action.

Role of Pheromones in Mate Selection

Pheromones play a crucial role in sexual attraction and communication between potential mates.

Sexual Behavior and Cultural Factors

Cultural influences can shape sexual behaviors and mating systems beyond biological determinants.

Temporal Patterns of Estrous Cycles

Estrous cycles exhibit temporal patterns that affect mating opportunities and reproductive strategies.

Competitive behavior in mating systems

Behavior exhibited by individuals competing for mates to enhance reproductive success.

Sociobiology

The study of social behaviors in animals, including mating strategies, from an evolutionary perspective.

Sexual imprinting

The process by which young animals develop preferences for certain mates based on early experiences.

Mate guarding

Behavior where one partner ensures the fidelity of the other to protect reproductive interests.

Sexual reproductive strategies

Different methods employed by species to maximize reproductive opportunities and success.

Secondary sexual characteristics

Physical traits that distinguish between the sexes and may influence mate attraction.

Mating displays

Behavioral displays by individuals to attract potential mates, including visual or auditory signals.

Social mating systems

Patterns of reproduction and relationship structures determined by social hierarchies and interactions.

Sperm competition

The competitive process where sperm from multiple males vie for fertilization of eggs.

Parental investment theory

The theory suggesting that the amount of care provided by parents influences reproductive strategies.

Copulatory lock

A phenomenon where male and female animals become temporarily physically locked together during mating, enhancing reproductive success.

Reproductive success

The passing of genes to the next generation, often measured by the number of offspring produced and their survival.

Mating call

Vocalizations made by male animals to attract females for mating, often characterized by specific patterns and frequencies.

Estrus cycle

The recurring period of sexual receptivity and fertility in female mammals, facilitating mating opportunities.

Courtship behavior

Various behaviors displayed by individuals to attract mates, including rituals, displays, and other actions.

Genital morphology

The study of differences in reproductive organ structure between males and females, often influencing mating strategies.

Sperm storage

The ability of female animals to store sperm after mating, allowing for fertilization at a later time.

Sexual selection pressures

Factors that influence which traits are favored in mating, affecting reproductive success over generations.

Environmental pressures on mating

External factors that can affect mating behaviors and success, such as habitat availability and competition.

Monogamous pair bonding

A mating strategy where one male mates exclusively with one female, often associated with high parental investment.