475 quizzes

NMDA receptors are often called "coincidence detectors". What two events must coincide in order to activate these receptors?

Glutamate binding postsynaptic depolarization-more positivity

Which of the following correctly describes a way that visual information can flow through the visual system?

Retina, optic nerve, thalamus to visual cortex

What are the output neurons of the retina?

Retinal Ganglion Cells

Above problem Determine what the Resting Membrane Potential of the cell is.

-41.9 mv

Which of the following is NOT directly regulated by hypothalamic activity?

none of the above

Decide whether the following items are associated with metabotropic (M) or ionotropic (I) receptors. Briefly describe each item.

(a) G-protein coupled receptors: M G-protein coupled receptors activate a signal transduction pathway when a neurotransmitter/ligand binds to them. (b) Rapid postsynaptic potentials:I Postsynaptic potentials (PSPs) that usually arise within a millisecond or two of a presynaptic AP, and last for only a few tens of milliseconds or less. (c) An ion channel:I a pore that can be opened to conduct positive or negative ions upon binding of a ligand neurotransmitter. Responds relatively quickly, compared to metabotropic receptors with a signal transduction pathway. (d) Longer-lasting postsynaptic responses:M Even though second-messenger systems respond slower, they also last for longer periods of time (hundreds of milliseconds to minutes).

Here is a list of neurotransmitters from lecture. For each statement, fill in the blank with the relevant neurotransmitter (each neurotransmitter may be used several times or not at all). your choices: Serotonin, GABA, norepinephrine, acetylcholine, nitric oxide, substance P, glutamate

(substance P) is a peptide neurotransmitter involved in pain transmission. (glutamate) is the most common excitatory transmitter in the human brain. (acetylcholine) acts on ionotropic receptors at the neuromuscular junction and both ionotropic and metabotropic receptors in the brain and affects higher functions such as learning, memory and cognition. (GABA) opens a chloride channel.

You are studying a cell with the following intracellular and extracellular ionic concentrations (mM): Ion Extracellular Intracellular Sodium 100 10 Potassium 10 100 Chloride 100 10 Membrane permeabilities are as follows: Sodium: 10 Potassium: 100 Chloride: 10 The cell is at room temperature. Determine what the equilibrium potential for chloride is

-58 Using the nernst equation: Eion=(+/-) 58log[ion]out[ion]in Ecl = - 58 log (100/10) = -58 mV *note, the negative preceding the equation comes from the fact that Cl is a negative ion

You identify a new neurotransmitter. In order to characterize the actions of this neurotransmitter, you conduct an experiment in which you stimulate a neuron containing your NT while recording the postsynaptic current using voltage clamp (let's you control the membrane potential, lines label the given voltages (-45 through -110)) . You get the following results: What is the reversal potential for this receptor? For didactic purposes, consider why you chose that value. You should be able to explain this choice on the exam.

-90mV

Which of the following is a function of the pinna?

Change sound to allow up/down localization

Though distinct neural circuits are implicated in the subjective, conscious experience of an emotion evoked by a stimulus VERSUS the behavioral response elicited by the same stimulus, many scientists still infer that the emotional state of an animal is reflected in its behavioral responses.

true The reason for this is that not only are the neural systems involved in the expression of an emotional behavior conserved, but so too are many connections in the brain that we know underlie conscious/subjective perception of emotion in humans. Darwin often argued that given evolutionary principles, the brains of humans and other animals are unlikely to be fundamentally different in kind, but rather, more likely to reflect differences in degree. i.e unlikely that animals DO NOT have emotions, more likely they may be less complex or nuanced than ours.

Figure 1 below shows data from one of the first experiments demonstrating LTP by Bliss and Lomo (1973; we looked at this in class). The y-axis represents measurements of fEPSP peak amplitude as a percent of baseline. The arrows indicate points at which high frequency stimuli were given. Figure 2 below depicts an example of a field EPSP prior to high frequency stimulation. The vertical line is the stimulus artifact (this is the fEPSP measurement WHILE the stimulation was happening - you can ignore it). What would the fEPSP look like at 1 hour? Choose from the following. Hint* it's only one of the following

2 times as large

Which of the following is NOT true about how the basilar membrane supports sound processing?

Allows us to identify the location of the sound source, especially in dogs

Curare is an acetylcholine receptor antagonist. What effect does curare have on the size and frequency of mEPPs ?

An acetylcholine receptor antagonist would bind to ACh receptors, preventing synaptic transmission. As such, if any mEPPs did occur in the context of curare, they would likely be smaller, as some proportion of the ACh released from a single vesicle would be blocked by curare, so the mEPP response would be smaller . In terms of mEPP frequency, the frequency would likely be the same, as that measure ultimately depends on the release of NT from the presynaptic terminal (which curare does not effect).

In the following diagram, the firing of which neuron will tell you that a sound source is exactly in front of your nose, halfway between your left and right ear? Which neuron will tell you when the location of a sound is coming from the closest to your right ear?

C and A week 12 quiz

Which of the following accurately describes a known anatomical pathway in the hippocampus? * hint, there are two correct answers!

CA3 to CA1 (areas) via the Schaffer collateral (axonal pathway) Entorhinal cortex to the dentate gyrus (areas) via the perforant path (axonal pathway)

Why is CaMKII a good candidate for a "molecular memory" molecule? Which of the following features of CaMKII explain how CAMKII can hold a 'memory' of synaptic activity? Hint* there are two correct answers.

CaMKII has the ability to phosphorylate itself (autophosphorylation) in order to turn off and on its function constitutively (until it is actively reversed) The enzymatic activities of CaMKII is dependent on Ca2+ concentration (Ca2+ is directly proportional to the strength of synaptic connection.)

What ion/s is/are most likely to have a high conductance through the channel described in the previous question? Remember the Eion for all the ions that affect the "model" neuron we described in module 1. * hint, this question has two correct answers.

Cl- K+

Aromatase is an enzyme that does which of the following?

Converts testosterone to estrogen

Which of the following signals comes from the stomach to activate hypothalamic neurons to increase feeding behaviors?

Ghrelin

Which of the following provided evidence of the Neuron Doctrine?

Electron microscopy methods allowed visualization of gaps separating neurons from their targets and synaptic vesicles in axon terminals Staining methods (developed by Golgi!) allowed visualization of single neurons and their processes

Which of the following is NOT true?

Extracellular recordings of neural activity have a much larger amplitude than intracellular recordings.

Which of the following applies to a description of the parasympathetic nervous system?

Facilitates feeding and mating behaviors

True/False. We now have evidence that humans are capable of magnetoreception because the molecule cryptochrome has been discovered in the retina.

False While it is true that cryptochrome is a molecule expressed in the human retina, the mechanisms that could allow it to TRANSDUCE magnetic fields into sensation are still unclear. Moreover, it has yet to be replicated and robustly demonstrated that humans can behaviorally sense/use magnetic fields to navigate or otherwise identify stimuli in their environment. This is NOT to say that it's impossible or doesn't exist, we simply have a lack of evidence so far for this sense in humans as well as a possible mechanisms that explains it. Both types of experiments are needed

Hebb's postulate from 1949 states "When an axon of cell A is near enough to excite cell B and repeatedly or persistently takes part in firing it, some growth process or metabolic change takes place in one or both cells such that A's efficiency, as one of the cells firing B, is increased." Which of the following are examples of how synaptic plasticity results in Metabolic processes? *Hint there are three correct answers.

Increases in presynaptic neurotransmitter release Changes in postsynaptic receptor density Changes in gene expression

Hebb's postulate from 1949 states "When an axon of cell A is near enough to excite cell B and repeatedly or persistently takes part in firing it, some growth process or metabolic change takes place in one or both cells such that A's efficiency, as one of the cells firing B, is increased." Which of the following are examples of how synaptic plasticity results in Growth processes? *Hint there are multiple correct answers.

Increases in the number and size of Spines Formation of New synapses

Which of the following is true about the process of sensitization?

It differs from habituation in that it is an INCREASE in responsiveness to the presentation of a stimulus due to a preceding intense stimulation event

Which of the following is true about how hair cells transduce mechanical vibrations into electrical signals?

K is the ion that mediates initial depolarization and ultimately voltage gated Ca channel opening to release neurotransmitter.

In the sentence below, add the correct terms.

LTD and LTP represent a continuum of modifications of synaptic strength. Low-frequency stimulation results in dephosphorylation of AMPA receptors, which results in endocytosis of the receptors. This results in synaptic depression.

For all forms of associative learning which of the following must be true? Hint, there are two correct answers.

Learned associations are generally longer lasting than a few seconds or minutes The new information associated with a behavior, must PRECEDE that behavior

Which of the following processes relies the LEAST on neural circuits embedded within the hippocampus?

Learning a new motor skill

Which of the following light stimuli will produce the most excitation in an ON-CENTER cell like the one shown below?

Light in the center of the receptive field only as shown in B. vision quiz

Select all that characterize a homeostatic process.

Maintains relative stability of physiological state Requires a sensor to determine when the system deviates from an optimal set point Responsive to system feedback

fill in the blanks

Many low-threshold mechanoreceptors ultimately send their signals to the spinal cord via the Heavily myelinated A-beta axon fiber type which facilitates relatively fast transduction of mechanosensation to the rest of the nervous system. This is in contrast to other mechanoreceptors that send their signals via the lightly myelinated A-gama fiber types with transmit electrical signals relatively slow to the spinal cord.

SUBJECTIVE emotional EXPERIENCE is associated with the function of which of the following brain areas?

Medial Prefrontal Cortex the evidence for this primarily comes from lesion and brain imaging studies in humans. However, it's likely to be more complex in terms of what Medial pre frontal is doing. It may be linking together the activity of a highly distributed network as opposed to "encoding" subjective awareness perse.

The following receptive field properties describe which cell type found in the retina? center surround structure small dendritic arbor color sensitive inactive at night or low light levels

Midget cells

Above info This cell has a chloride transporter which maintains the chloride concentration inside the cell. Which direction does the transporter move chloride across the membrane?

Outwards

Which of the following is true when considering the differences between rods and cones?

Rods respond best in a dimly lit environment.

The amplification ability of the photoreceptor cells that provides them with their sensitivity is primarily explained by which of the following aspects of signal transduction?

Second messangers

A key feature of olfactory processing is strong adaptation to persistently present odor compounds. Odor detection first begins in olfactory sensory neurons through the activation of a G-protein coupled receptor, which ultimately leads to Ca channel opening and cellular depolarization. However, the process of adaptation is also stimulated by increases in Ca levels and the activation of CamKII. Therefore, if an animal has a mutation in the gene that encodes for Adenyl Cyclase (ACII) that renders it UNRESPONSIVE to CamKII in olfactory sensory neurons, it will remain constitutively active. What of the following is a consequence of this altered activity of ACII?

Sensory neurons will take longer to adapt to a constant stimulus

What is a miniature end-plate potential (mEPP)? Select all that apply.

Small postsynaptic responses of a unitary size, or multiples of that size Spontaneous postsynaptic responses in the absence of a presynaptic action potential

In the olfactory bulb, the representation of a given odor is combinatorial such that a given odor at a given concentration will reliably activate a subset of Olfactory Sensory Neuron (OSN) types. This subset of OSNs and how much they are activated is distinct from that which a different odor activates. Therefore, which of the following is predicted for two odors that perceptually smell very SIMILAR?

They both bind to similar types of GPCRs (olfactory receptor types)

The term Modality when discussed in the context of sensory processing refers to...

The physical nature of a stimulus that can be sensed and the way it is processed by the nervous system

Which of the following would provide evidence that animals have acquired new COGNITIVE knowledge of a relationship between a formerly novel stimulus and the reward they learn it predicts?

They demonstrate an understanding of a "rule" that predict reward regardless of whether the specific stimuli have been previously experienced.

A model cell has only potassium channels in its membrane. The concentration of potassium is larger inside the cell than outside. The concentration of sodium is larger outside the cell than inside. The concentration of chloride is equal inside and outside. True or False: The membrane potential of the cell is negative.

True

If a synapse only contains AMPA and NMDA receptors, AMPA receptors may be activated without also activating NMDA receptors. However, it is unlikely that the NMDA receptors may be activated without also activating AMPA receptors first.

True If a synapse only contains AMPA and NMDA receptors, AMPA receptors may be activated without also activating NMDA receptors. However, it is unlikely that the NMDA receptors may be activated without also activating AMPA receptors first. True, This is because of the Mg2+ blockade property of NMDARs. It requires that recent depolarization precedes NMDAR activation. This state is likely to be induced by the AMPA type receptors in this case as it's the only type of receptors available to this synapse.

A cell has an internal potassium concentration of 10 mM and an external potassium concentration of 1 mM. It has an internal sodium concentration of 10 mM and an external concentration of 200 mM. The permeability of the membrane to potassium is 100, the permeability to sodium is 10. The membrane is not permeable to any other ions. Which of the following is true?

You have to use the GHK equation to determine this answer The resting membrane potential is closer to the sodium equilibrium potential.

Humans use a combination of Binaural (needs two ears) and Monaural cues (only needs to be detected in one ear) to spatially localize the source of a sound. Which of the following aids humans and other mammals to localize the source of a sound? *there are two correct answers

changing the position of your ears along the vertical axis ITD and ILD

Fruitless is a gene that regulates whether or not a fly turns out homosexual.

false

True/False? The retina does not process visual information before sending it off to the brain.

false

True/False? The retina is the main source of synaptic input to the LGN.

false

Memory is just a single process described by a single molecular and cellular basis localized to hippocampal circuits.

false Memory (recall) is highly complicated, especially explicit forms. There is evidence that, at the very least, memory can be subdivided into 4 processes each regulated by different molecular processes and some occurring in distinct brain regions and circuits : 1) encoding 2) consolidation 3) storage and 4) retrieval . If you're interested to learn more, look up about how NMDA receptor specifically contribute to encoding of memory in specific hippocampal circuits, AMPA receptors and neuromodulators such as acetylcholine contributing to retrieval from cortical circuits coupled to CA3 in hippocampus and PKM zeta and memory consolidation, storage and "forgetting"

If a male child endures a botched circumcision and the doctor turns him into a female by removing his testes and creating a vagina, that individual will never know the difference because sex hormones only influence behaviors and the brain after puberty.

false this happened to a real person! And, "he" knew he didn't "feel" female and confronted his parents. The organizing effects of sex hormones on the developing brain and behavior are significant and it is hypothesized to contribute to sexual identify and more complex sexual behaviors in the adult. However, we still do not know the full extent of these effects nor clearly understand how much overall influence they contribute towards adult sexual identity and behavior.

Activation of either POMC or AgRP neurons causes mice to feed more.

false to get the full study benefit of this question, carefully review the location, activation and activity relationships between these neurons and feeding behaviors.

Which of the stimulus responses shown below came from a low-threshold and rapidly adapting mechanoreceptor sensory neuron?

left quiz week 10

What would happen to the response shown on the fEPSP plot at 5 hours if Bliss and Lomo had given a low frequency stimulation of about 1 Hz just after 4 hours?

the fEPSP would be smaller than the response at 4 hours

The somatosensory homunculus represents the amount of "real-estate" taken in the brain to processes information from specific parts of the body. This representation makes it apparent that we do NOT process information from all parts of the body with equal sensitivity.

true

Transduction of sound waves into electrical activity in hair cells is unique relative to signal transduction in photoreceptor neurons and olfactory sensory neurons because mechanical motion of the cells is directly translated into the opening of cation channels which rapidly lets in K+ leading to the opening of voltage gated Ca2+ channels and the rapid release of glutamate.

true

True or False? There are both sequential and parallel flows of information through the visual system.

true

True/False? Photoreceptors hyperpolarize when light hits them, stopping the release of neurotransmitters when illuminated.

true

True/False? The output of a retinal ganglion cell depends on its receptive field, which consists of input from multiple cells

true

True/false? Photoreceptors are unevenly distributed across the retina of the human eye?

true