Mechano
This term refers to the way the size of potential change in sensory receptors are encoded by firing frequency of the postsynaptic neuron(s)
Frequency coding
Vertebrate olfactory receptors are what type of receptor protein?
GPCRs
What directly activates transducin, and what does this cause?
Transducin is a G-protein activated by the light-induced conformational change of rhodopsin (metarhodopsin). This leads to the activation of phosphodiesterase which breaks down cGMP into GMP, reducing the number of open sodium channels
What effect does increasing external sodium concentration have on the equilibrium potential of sodium?
Increasing external sodium concentration shifts its equilibrium potential to a more positive value
What is the importance of reducing the outward potassium current during short-term sensitization?
This increases the duration of the depolarization, allowing for greater amounts of calcium to accumulate, increasing release probability of NT
What sorts of stimuli can activate a mechanoreceptor?
Temperature, pressure, vibration, texture
Olfactory receptor cells directly project onto what type of neurons?
Mitral cells (and/or tufted cells)
Visual acuity (sharpness) is brightest in this region of the eye that has the highest density of cone photoreceptors
The fovea
During this period following an action potential, there is a heightened threshold for firing, but the cell remains depolarized and voltage-gated sodium channels are recovering from inactivation
Relative refractory period
Blockage of ryanodine receptors blocks this kind of LTP while blockage of mGluR blocks this kind of LTP
LTP 1
LTP 2
The stretch-opening of tip links on stereocilia have what effect on the auditory hair cell membrane?
Opening potassium channels, depolarizing the hair cells
This receptor subtype is responsible for the bitter taste response
TRPM5
What is required for the inward sodium current in photoreceptors in the absence of light?
cGMP
This type of glial cell controls the concentration of certain ions and neurotransmitters at the synapse
Astrocytes **
What is required for the conversion of silent synapses to functional synapses?
Sufficient depolarization/input from other cells neighboring regions
__ motor neurons control the contracting of intrafusal muscle fibers while __ motor neurons control contracting of extrafusal muscle fibers
Gamma
Alpha
Reducing intracellular calcium signaling in primary taste receptors has what effect on taste receptors that respond to sour flavors?
Nothing. Sour taste is processed through an ionotropic receptor while other flavors (sweet, bitter, and umami) are processed by GPCRs and require the release of calcium from intracellular calcium stores
What change in intracellular calcium signaling promotes photoreceptor adaptation?
Lower calcium - less cGMP degradation, more cGMP synthesis, stronger dark current
Define resistance, capacitance, and conductance. What is the relationship between these and voltage?
Resistance is the inverse of conductance, and both have to do with how easy/difficult it is for ions to pass through the membrane. Capacitance is the ability to store charge
Voltage is equal to either resistance times current, or current divided by conductance
Application of BAPTA has what effect on homosynaptic LTD?
Reduces LTD
This term refers to the decrease in firing frequency of a postsynaptic cell following prolonged, sustained levels of stimulation
Adaptation
What receptor subtype is responsible for sour taste?
OTOP1
How does phototransduction in invertebrates differ from that of vertebrates?
Light depolarizes photoreceptors in invertebrates through G-protein coupled release of calcium from intracellular stores
Light hyperpolarizes photoreceptors through the activation of retinal, which triggers the breakdown of cGMP into GMP, making it unavailable to bind to and open sodium channels.
Describe the movement of the two main ions underlying the action potential (ionic currents). How do we know?
First - early inward sodium current - blocked by TTX (tetrodotoxin)
Second - outward sodium current - blocked by TEA (tetraethyl ammonium)
NMDA receptors are NOT associated with what kind(s) of LTP?
LTP 3