Process at the end of a developing axon that reaches out to search for a potential target or to sample the intercellular environment.

Range of cognitive symptoms from mild to severe that characterize autism; severe symptoms include greatly impaired social interaction, a bizarre and narrow range of interests, marked abnormalities in language and communication, and fixed, repetitive movements.

Hypothesis that the processes of cell death and synaptic pruning are, like natural selection in species, the outcome of competition among neurons for connections and metabolic resources in a neural environment.

Genetically programmed cell death.

Path-making cell that a migrating neuron follows to its appropriate destination.

Structure in the early stage of brain development from which the brain and spinal cord develop.

Proposal that neurons or their axons and dendrites are drawn toward a signaling chemical that indicates the correct pathway.

Self-renewing multipotential cell that gives rise to any of the different types of neurons and glia in the nervous system.

Lining of neural stem cells surrounding the ventricles in adults.

Failure of the forebrain to develop.

Product of a progenitor cell that gives rise to different types of glial cells.

Brodmann areas 9 and 46; makes reciprocal connections with posterior parietal cortex and the superior temporal sulcus; responsible for selecting behavior and movement with respect to temporal memory.

Primitive neural tissue that gives rise to the neural tube.

Class of hormones that stimulates or controls masculine characteristics and level of sexual interest.

Sex hormone secreted by the testes and responsible for the distinguishing characteristics of the male.

Unexplained death while asleep of a seemingly healthy infant less than 1 year old.

Developmental window during which some event has a long-lasting influence on the brain; also, sensitive period.

A chemical compound that supports growth and differentiation in developing neurons and may act to keep certain neurons alive in adulthood.

Variety of sex hormones responsible for the distinguishing characteristics of the female.

Formation of an attachment by an animal to one or more objects or animals at a critical period in development.

Signaling molecule that attracts or repels growth cones.

Member of the only class of tropic molecules yet isolated.

Growing tip of an axon.

Product of a progenitor cell that gives rise to any of the different types of neurons.

A chemical molecule to which specific cells can adhere, thus aiding in migration.

Derived from a stem cell; it migrates and produces a neuron or a glial cell.

Condition in which vision in one eye is reduced as a result of disuse; usually caused by a failure of the two eyes to look in the same direction.

Sporadic period of sudden growth that lasts for a finite time.

Process by which exposure to androgens (male sex hormones) alters the brain, rendering it identifiably male.