{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

BIO203_Synapse - Synaptic Transmission Electrical Synapses...

Info icon This preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
1 Synaptic Transmission Electrical synapses Rapid cell-to-cell transfer of electrical activity from one cell to another cell Gap junction-mediated electrical current flow Chemical synapses Slower cell-to-cell transfer Signal transfer across synaptic cleft via secretion of diffusible chemical messenger(s) Electrical Synapses Sherwood, Klandorf & Yancey, Animal Physiology: From Genes to Organisms , Figures 2-34, 9-20 Passive (electrotonic) current flow from pre- synaptic (signal-sending) cell to post-synaptic (signal- receiving) cell High degree of gap junctional coupling produces a functional syncytium for coordinated activity of the population of “electrically coupled” cells Non-directional: capable of passing current in both directions under experimental conditions CARDIAC MUSCLE Chemical Synapses Pre-synaptic and post-synaptic cells separated by a synaptic cleft action potential enters axon terminal of pre-synaptic cell depolarization of synaptic knob causes opening of voltage-gated Ca 2+ channels • Ca 2+ enters synaptic knob • Ca 2+ -stimulated exocytosis of synaptic vesicles containing chemical neurotransmitter neurotransmitter diffusion across synaptic cleft (adds delay) neurotransmitter reception by ligand-gated ion channels in post- synaptic cell membrane depolarization or hyperpolarization of post-synaptic cell membrane according to nature of neurotransmitter and ion channel The effect on the post-synaptic cell is: excitatory if the post-synaptic cell membrane is driven toward the
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern