BIOL 031 002 1st Edition Lecture 2 Outline of Last Lecture I Reading Behavior Why it Matters II The Herding Instinct III Ren Descartes IV The Inconsistent Tetrad V Three Main Approaches to Studying the Neuroscience of Behavior VI Levels of Analysis in Biological Psychology VII Relationships among Biological Psychology VIII Your Brain by the Numbers IX The Ties That Bind X Five Research Perspective Applied to Three Kinds of Behavior Outline of Current Lecture Neuroanatomy I Four Different Traditions for Understanding the Brain II The Reticular Theory gives way to the Neuron Doctrine III Neurons and Connectivity IV A Sense of Scale V Three different Types of Neurons VI Visualizing Neurons VII Four General Features of Studying Neurons VIII The Synapse IX Distinctions Between Axons and Dendrites X Neuronal Trafficking XI Glial Cells XII Peripheral and Central Nervous Systems XIII The Twelve Cranial Nerves XIV The Spinal Cord Spinal Nerves Current Lecture Neuroanatomy The brain is a beautiful thing Dr Blumberg I Four Different Traditions for Understanding the Brain A Take these classic sciences and put neuro in front of it 1 Anatomy Neuroanatomy 2 Physiology Neurophysiology 3 Pharmacology Neuropharamacology 4 Behavior Psychology and Biology B Neuroethology study of the brains of animals in their natural habitat C Side note Michelangelo the artist stole bodies from the morgue to study human anatomy II The Reticular Theory gives way to the Neuron Doctrine A Camillo Golgi s reticular theory that neurons are continuous with one another forming a nearly endless network B Camillo Golgi invented the technique of staining nerve cells 1 Ink injected ink is attracted to cells nerve cells become more prominent and easier to research 2 Today it is still called the Golgi stain C Ramon y Cajal had a differing theory that neurons come very close to one another but there is a tiny gap to keep the cells separate D These scientists made important advances in understanding the basic structure of the nervous system 1 The culmination of this work was the so called neuron doctrine 2 Neuron doctrine the nervous system is composed of discrete signaling units called neurons that are independent structurally metabolically and functionally and information is transmitted from cell to cell across tiny gaps synapses III Neurons and Connectivity A In the 80 s there were only four neurotransmitters identified now there are hundreds 1 There are also hundreds of neuroreceptors neurochemicals identified B This relationship functioning of these neurons is what allows us to have the ability to do anything C Remember that what makes us humans functional is the fact that we can move around 1 The brain is embodied it is not a separate entity from our body D In neuroscience we try to understand what and how information is being sent and received by neurons E Neurons are constantly giving and receiving bits of information 1 These neurons create a field of networks F Major Parts of the Neuron Including four functional zones and specific parts in order 1 Input zone part of the neuron that receives information from other neurons Dendritesone of the extensions of the cell body that are the receptive surfaces of the neuron 2 Integration zone part of the neuron that initiates nerve electrical activity Cell Bodyalso called soma region of the neuron that holds the cell nucleus 3 Conduction zone part of the neuron over which the nerve s electrical signal may be actively reproduced Axon single extension from the nerve cell that carries nerve impulses from the cell body to other neurons 4 Output zone part of the neuron usually corresponding to the axon terminals at which the cell sends info to another cell Axon terminals also called the synaptic bouton the end of an axon or axon collateral which forms a synapse on a neuron or other target cell IV A Sense of Scale A View Firing Neurons video 1 http www youtube com watch v GIGqp6 PG6k 2 Speed at which information is sent and received between neurons is extremely rapid V Three Different Types of Neurons pg 28 in the textbook A There is a diversity of ways to construct a neuron 1 Multipolar Neuron has many dendrites extending from the cell body 2 Bipolar Neuron has a single dendrite extending from the cell body 3 Unipolar neuron has a single branch that emerges from the cell body and extends in two directions VI Visualizing Neurons A Different ways to see the neurons 1 The Golgi stain 2 Neurons injected with fluorescent dye different colored dyes indicate what cells they will be attracted to 3 Nissl stain specifically stains cell bodies 4 There is a dye that is attracted to recently activated cells 1 c fos gene this gene is expressed when an activity has been done a The proteins in these c fos genes can be stained so scientists can process what recent activity has been done VII Four Different Features of Studying Neurons A Because neurons are the basic unit of processing the brain we can learn a lot about the brain by studying them in detail and by paying special attention to these four general features 1 The mechanisms by which neurons produce their signals 2 The ways in which neurons are connected 3 The relationship between the patterns of connections between neurons and different types of behavior 4 The means by which neurons and their inter connections are modified by experience neural plasticity learning VIII The Synapse pg 30 in the textbook A Presynaptic region of the synapse that releases neurotransmitter B Postsynaptic region of the synapse that receives and responds to neurotransmitter C There is never any physical contact between the presynaptic and the postsynaptic D Any medication stimulants brain altering substances will affect this specific area IX Distinctions between Axons and Dendrites pg 31 in the textbook A Axons 1 Usually one per neuron with many terminal branches 2 Diameter is uniform until the start of terminal branching 3 Join cell body at a distinct region called the axon hillock 4 Usually covered with myelin 5 Lengths from practically nonexistent several meters 6 Along length branches tend to be perpendicular B Dendrites 1 Usually many per neuron 2 Diameter tapers progressively toward its ending 3 No hillock like region 4 No myelin covering 5 Usually much shorter than axons 6 Along lengths branches occur over wide range of acute angles The axon has molecular machines that move chemicals information to axon terminals X Neuronal Trafficking A View Real time