1. 26th August 2013Bio 334 - Neurobiology I - Organization of the nervous system 31 Organization of the nervous system 3 Raghav Rajan Bio 334 – Neurobiology I August 26th 2013

2. 26th August 2013Bio 334 - Neurobiology I - Organization of the nervous system 32 Spinal cord ● Dorsal roots carry sensory information ● Ventral roots carry motor information ● Controls voluntary and reflexive movements ● Receives sensory input from skin, joints, muscles ● Paralysis inferior to location of damage Mark F Bear, Barry W Connors, Michael A Paradiso. Neuroscience: Exploring the brain (2007) – Chapter 7

3. 26th August 2013Bio 334 - Neurobiology I - Organization of the nervous system 33 PNS ● Somatic PNS – related to voluntary control ● Visceral PNS – involuntary – innervates internal organs, glands, blood vessels, etc. http://en.wikipedia.org/wiki/Peripheral_nervous_system

4. 26th August 2013Bio 334 - Neurobiology I - Organization of the nervous system 34 General functions of nervous system ● To find food ● To avoid being eaten ● To reproduce

5. 26th August 2013Bio 334 - Neurobiology I - Organization of the nervous system 35 Evolution of complex nervous systems ● Evolution selects for adaptations that promote the ability to pass on genetic material ● Works on what is already there ● Needs some amount of redundancy to tinker and make changes

6. 26th August 2013Bio 334 - Neurobiology I - Organization of the nervous system 36 General principles of organization of nervous system ● Organization of sensory and motor areas dependent on environment, relative importance of different sense organs, motor capabilities ● Based on anatomy, we can delineate functional systems ● Functional systems are organized into maps ● Hierarchy of functional systems? ● Functional systems on one side of the brain (cerebral cortex) get information and control the contralateral side of the body Kandel, Schwartz and Jessell, Principles of Neural Science

7. 26th August 2013Bio 334 - Neurobiology I - Organization of the nervous system 37 Sensory and motor cortical representations not proportional to external size http://www.autismindex.com/Therapies/Therapy_Key_Word_Site_Map/sensory/motor_sensory_homunculus.html

8. 26th August 2013Bio 334 - Neurobiology I - Organization of the nervous system 38 Important sensory organs are better represented in the cortex and sub-cortical structures http://www.pnas.org/content/109/Supplement_1/10647.long

9. 26th August 2013Bio 334 - Neurobiology I - Organization of the nervous system 39 Functional systems – like the visual system – two streams of processing ● Dorsal pathway - “vision for action” - where ● Ventral pathway - “vision for perception” - what ● Now, considerable evidence for interaction between both pathways http://www.waece.org/cd_morelia2006/ponencias/stoodley.htm

10. 26th August 2013Bio 334 - Neurobiology I - Organization of the nervous system 310 Maps – sensory, motor, etc. http://uc.exteenblog.com/highwind/images/Know/brain_homunculus1.jpghttp://w ww.wiringthebrain.com/2010_12_01_archive.html http://neurowww.cwru.edu/faculty/strowbridge/OlfactoryBulb/bulb1.htm http://www3.unil.ch/wpmu/neuroaudio/resaerch/auditory-cortex/

11. 26th August 2013Bio 334 - Neurobiology I - Organization of the nervous system 311 Hierarchichal processing within functional systems – is there really a hierarchy? Felleman DJ, Van Essen DC. Distributed hierarchical processing in the primate cerebral cortex. Cerebral Cortex (1991) http://www.cse.buffalo.edu/~rapaport/575/F07/006010.jpg

12. 26th August 2013Bio 334 - Neurobiology I - Organization of the nervous system 312 Plasticity – changes in strength of connections not reflected in simple anatomy ● In congenitally blind people, primary visual cortex is active during sentence comprehension task http://www.pnas.org/content/108/11/4429.long

13. 26th August 2013Bio 334 - Neurobiology I - Organization of the nervous system 313 Assignment on disorders ● 1 page write-up – in layman language ● Description of disorder ● Present understanding of the cause? ● What does this tell us about the brain? ● Caveats ● Send by email before the 2 nd of September