Biopsychology Winter 2022 | Maya Varghese

Signals Across The Synapse While transmission of a signal along an axon is electrical, transmission between neurons is chemical. The chemicals used to signal are known as neurotransmitters, and the neuron synthesizes them in the axon terminals. Neurotransmitters There are about a hundred chemicals that are either confirmed or suspected neurotransmitters. Most fall into the following categories: Amino acids Modified amino acids/monoamines Includes serotonin, dopamine, norepinephrine, ephinephrine Neuropeptides, which are chains of amino acids Includes endorphins Purines Gases     Neurons make most neurotransmitters by modifying amino acids. For example, catecholamines, which includes dopamine, epinephrine, and norepinephrine, are made by attaching a catechol group to an amine group. These three all come from phenylanine. Serotonin comes from tryptophan (found in soy). We get these amino acids from our diet. Neurons keep supplies of neurotransmitters in the axon terminal after synthe

 The Cells of the Nervous System There are only two kinds of cells that make up the nervous system. Neurons are the ones we hear the most about, as they’re the ones that actually receive and transmit information. Glia perform many functions to support the nervous system’s work. Neurons There are a lot of neurons in our brains -- the average adult has 86 billion, plus another billion in the spinal cord. However, it varies from person to person. In addition to the organelles most cells have, like a nucleus, mitochondria, and ribosomes, neurons have unique structures. The main parts of a neuron are the: Soma: the main cell body, containing typical cell organelles Dendrites: branching fibers lined with synaptic receptors to receive information from other neurons Axon: a thin fiber which conveys an impulse. The impulse can be headed to other neurons, an organ, or a muscle. Axons can be very long -- we have axons that stretch from our spinal cords to our feet. The end of an axon has one

Biopsychology is about what it sounds like -- the biological aspects of psychology. This means it’s primarily concerned with the brain and how it functions, but also aspects of genetics and evolution that contribute to our psychology. So, the content of this class will primarily be about the brain, and also about genetics and evolution. But the primary question of biopsychology, at least according to the book, is to understand the relation between biology and consciousness. It states upfront that there’s no good answer to what consciousness even is, let alone what about our biology makes it possible. But interrogating the question is part of grappling with the material. Psychology assumes consciousness; I’m not sure the field could exist without that assumption. And biology mostly isn’t about the problem of consciousness; it’s about the science of what we know is definitely happening in living organisms. But we know that the biology of an individual person -- the genes they inherit, th