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Physical modifications important for consolidating memory are particularly apparent in the hippocampus, especially a pathway called the Schaffer Collateral, which contains CA1 (cornu Ammonis) neurons that have been implicated in learning and memory. To study learning and memory in live mice, scientists use a stimulating electrode to generate brief electrical pulses on the dendrites of CA1 neurons in the Schaffer Collateral pathway and use a recording electrode to measure the excitatory postsynaptic potentials (EPSPs) in the CA1 postsynaptic neurons.In Study 1, researchers used brief low-frequency stimulations (1-5 stimuli per second) to establish a baseline response in the CA1 postsynaptic neurons. Then, the same dendrites were given a high-frequency stimulation (50-100 stimuli per second) , referred to as a tetanus. The researchers discovered that the high-frequency tetanus induced an increase in the response in postsynaptic CA1 neurons that was long-lasting. For the control, the researchers established a baseline in a second set of CA1 neurons in the same region but did not give a high-frequency tetanus (Figure 1) .
Figure 1 CA1 neuron response after a brief tetanus (experimental) or no tetanus (control) In a second behavioral study, mice were housed in either a standard cage (control) or a cage with an enhanced learning environment, including toys and access to a running wheel (experimental condition) . For the first 12 days, both groups of mice received injections of a dye that is incorporated into newly synthesized DNA, thereby providing a biomarker of neurogenesis.Following 30 days in their respective environments, all mice were tested each day for one week in the Morris Water Maze, a test that measures spatial learning and memory consolidation. Results showed that mice in the experimental condition demonstrated greater improvement on Morris Water Maze performance compared to controls. When hippocampi were examined, the results revealed that mice in the experimental condition had a greater number of dye-labeled cells than did the controls.
W. C. Abraham, B. Logan, J. M. Greenwood, and M. Dragunow ©2002 The Society of Neuroscience, and H. van Praag, B. R. Christie, T. J. Sejnowski, and F. H. Gage ©1999 National Academy of Sciences.
-In Study 2, what type of human memory is most analogous to the type of memory assessed in mice?

Question

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Physical modifications important for consolidating memory are particularly apparent in the hippocampus, especially a pathway called the Schaffer Collateral, which contains CA1 (cornu Ammonis) neurons that have been implicated in learning and memory. To study learning and memory in live mice, scientists use a stimulating electrode to generate brief electrical pulses on the dendrites of CA1 neurons in the Schaffer Collateral pathway and use a recording electrode to measure the excitatory postsynaptic potentials (EPSPs) in the CA1 postsynaptic neurons.In Study 1, researchers used brief low-frequency stimulations (1-5 stimuli per second) to establish a baseline response in the CA1 postsynaptic neurons. Then, the same dendrites were given a high-frequency stimulation (50-100 stimuli per second) , referred to as a tetanus. The researchers discovered that the high-frequency tetanus induced an increase in the response in postsynaptic CA1 neurons that was long-lasting. For the control, the researchers established a baseline in a second set of CA1 neurons in the same region but did not give a high-frequency tetanus (Figure 1) .

Figure 1 CA1 neuron response after a brief tetanus (experimental) or no tetanus (control) In a second behavioral study, mice were housed in either a standard cage (control) or a cage with an enhanced learning environment, including toys and access to a running wheel (experimental condition) . For the first 12 days, both groups of mice received injections of a dye that is incorporated into newly synthesized DNA, thereby providing a biomarker of neurogenesis.Following 30 days in their respective environments, all mice were tested each day for one week in the Morris Water Maze, a test that measures spatial learning and memory consolidation. Results showed that mice in the experimental condition demonstrated greater improvement on Morris Water Maze performance compared to controls. When hippocampi were examined, the results revealed that mice in the experimental condition had a greater number of dye-labeled cells than did the controls.
W. C. Abraham, B. Logan, J. M. Greenwood, and M. Dragunow ©2002 The Society of Neuroscience, and H. van Praag, B. R. Christie, T. J. Sejnowski, and F. H. Gage ©1999 National Academy of Sciences.
-In Study 2, what type of human memory is most analogous to the type of memory assessed in mice?

Quizplus · Accepted Answer

11ecba2d_0ce4_d2b9_a3bf_eda5207a5e37_MD0008_00 Research suggests that humans have two major, long-term memory systems, referred to as explicit and implicit. Implicit memory does not require conscious thought. A type of implicit memory, procedural memory involves learning motor skills, such as riding a bicycle, playing an instrument, or tying shoes. In Study 2, the water maze is a spatial and motor task requiring information that is most analogous to what might be stored in implicit memory. Explicit memory can be consciously or intentionally recalled. Explicit memory is often referred to as declarative memory, which is memory for facts and events. Declarative memory includes episodic memory, which is the memory for personal experiences (eg, your first day of college), and semantic memory, which includes fact-based knowledge (eg, name of the first US president) and language (eg, "their" and "there" are not synonymous). (Choice A) Sensory memory is the very brief temporary storage of sensory information (eg, sights, sounds, smells). Much information comes into the sensory memory store, but anything that does not move on to the next system, short-term memory, is almost immediately lost. Although sensory memory is required to complete spatial/motor tasks like the Morris Water Maze, it is not what is being assessed in the second study. (Choices B and C) Episodic and semantic memory are forms of explicit memory, which is not the type of memory required to solve a spatial/motor task such as the Morris Water Maze. Educational objective: Procedural memory, a type of implicit memory, is long-term memory for learned motor skills and is not consciously accessible. Explicit memory, or declarative memory, is long-term memory for facts (semantic) or personal events (episodic) and is consciously accessible.

Passage Physical Modifications Important for Consolidating Memory Are Particularly Apparent in in the Hippocampus