1. Methods in Neuroscience

sensory system

part of the NS that reports info about the state of the organism and environment

motor system

part of the NS that organizes and generates movement

associational system

part of the NS that provides higher order brain functions, such as perception, attention, memory, emotions, language, and thinking

central nervous system

part of NS subdivided into brain and spinal cord

peripheral nervous system

part of NS subdivided into sensory, somatic, and autonomic divisions

reticular theory

idea that all neurons form a continuously connected network

neuron doctrine

neurons communicate at synapses rather than through physical activity

neuron

NS cell which processes info, senses environmental changes, communicates changes via electrical signaling, and controls body responses

dendrite

branchy target for synaptic input from axon terminals of other neurons whose complexity increases with the number of inputs

axon

shaft responsible for signal transduction from cell body; reads out info

action potential

all or nothing changes in electrical potential made by Nodes of Ranvier, requiring Na to allow neuron to reach threshold and K to bring it back down

Node of Ranvier

gap between myelin that propagates action potentials

saltatory conduction

action potentials jumping between Nodes of Ranvier, enhancing velocity

presynaptic terminal

where molecules are secreted into synaptic cleft, immediately adjacent to dendrite of next cell

postsynaptic specialization

areas of dendrites w/ receptors for molecules to bind, immediately adjacent to axon terminal of previous cell

synaptic cleft

gap between pre- and post- synaptic terminals

glia

NS cell which supports the signaling function of, insulates, nourishes, and supports neurons; includes astrocytes, oligodendrocytes, Schwann cells, microglia, and stem cells

astrocyte

CNS glial cell maintaining appropriate chemical environment for neuronal signaling, including blood-brain barrier formation

oligodendrocyte

CNS myelin generator

Schwann cell

PNS myelin generator

microglia

scavenger cells that remove cellular debris from injury sites and cell turnover, secrete cytokines

glial stem cell

precursor to glia

afferent

carries info to CNS

efferent

carries info away from CNS

interneuron

CNS cell that participates in local aspects of circuit function, such as DRG

agonist

muscle that performs target movement (extensor in knee jerk reflex)

antagonist

muscle that opposes target movement (flexor in knee jerk reflex)

divergent circuit

neural circuit that spreads info

convergent circuit

neural circuit that integrates info

electrophysiological recording

technique to probe neural circuit function, subdivided into intracellular and extracellular recording

extracellular recording

an electrode is placed outside a neuron to detect temporal patterns of AP activity

intracellular recording

an electrode is placed inside a neuron to detect small. graded changes in electrical potential that can trigger APs and assesss communication among neurons w/in a circuit

calcium imaging

recording transient changes in [Ca] ion associated w/ AP firing to infer neural activity changes, where neurons are labeled w/ a Ca sensitive dye and then imaged

optogenetic

method introducing opsins into the NS so a neuron can artificially fire from light to assess neural circuit activity

opsin

bacterial channels transducing light energy into chemical signal activating channel proteins