Neuroscience Review

Outline Communication within a neuron Communication between neurons Action potential, ion gradients Communication between neurons Neurotransmitters and receptors Signal transduction pathways Response to external stimuli Sensory systems

Life cycle of neurotransmitters: chemical transmission

Classical Neurotransmitters Acetylcholine Dopamine Norepinephrine Serotonin Glutamate GABA Glycine Synthesized by enzyme Stored in vesicles Regional specificity Secreted factors Bind receptor Specific, saturable Produce effect in target cells Degradation/uptake

Novel Neurotransmitters Endocannabinoid, lipids Produced on demand Act presynaptically Peptides Synthesized from genes, processed in vesicles by enzymes NO, CO gasses Short lived, diffusible across membranes Adenosine, ATP nucleosides Very short lived

Insulin Signaling Pathway -Conserved -Lifespan -Survival -Neural Plasticity Components: -ligand -receptor -kinases -transcription factors

Response to Stimuli Integration of internal and external states leads to behavior, which modifies state and feeds back to further refine decisions and actions

Levels of processing, behavior choices Cortical—external Sub-cortical—internal

Human Brain ~1 trillion cells—neurons and glia.

Most common laboratory models. Rodent Brain

Mouse hippocampus—”brainbow”

Drosophila (fruit fly) brain ~100,000 neurons, most popular genetic model system, most advanced neuroscience circuit research. Dr. Miesenbock, 2009. Here, they activated Kenyon cells, which produce DA and are necessary for avoidance of electric shock, with a light activated ion channel, at the same time exposed to a strong odor. Learned to avoid the odor.

Drosophila (fruit fly) brain The “brainbow”, mixed fluorescent proteins combine to produce 100 unique hues enabling researchers to separate out and trace individual axons and dendrites.