Medial Prefrontal-Hippocampal Connectivity and Motor Memory Consolidation in Depression and Schizophrenia

Motor learning and memory consolidation require the contribution of different cortices. For motor sequence learning, the primary motor cortex is involved primarily in its acquisition. Premotor areas might be important for consolidation. In accordance, modulation of cortical excitability via transcranial DC stimulation (tDCS) during learning affects performance when applied to the primary motor cortex, but not premotor cortex. We aimed to explore whether premotor tDCS influences task performance during motor memory consolidation. The impact of excitability-enhancing, -diminishing, or placebo premotor tDCS during rapid eye movement (REM) sleep on recall in the serial reaction time task (SRTT) was explored in healthy humans. The motor task was learned in the evening. Recall was performed immediately after tDCS or the following morning. In two separate control experiments, excitability-enhancing premotor tDCS was performed 4 h after task learning during daytime or immediately before conduction of a simple reaction time task. Excitability-enhancing tDCS performed during REM sleep increased recall of the learned movement sequences, when tested immediately after stimulation. REM density was enhanced by excitability-increasing tDCS and reduced by inhibitory tDCS, but did not correlate with task performance. In the control experiments, tDCS did not improve performance. We conclude that the premotor cortex is involved in motor memory consolidation during REM sleep.

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Sigma Oscillations Protect or Reinstate Motor Memory Depending on their Temporal Coordination with Slow Waves

10.1101/2021.09.02.458683 ◽

2021 ◽

Author(s):

Judith Nicolas ◽

Brad R King ◽

David Levesque ◽

Latifa Lazzouni ◽

Emily BJ Coffey ◽

...

Keyword(s):

Beneficial Effect ◽

Memory Consolidation ◽

Crucial Role ◽

Motor Performance ◽

Irrelevant Information ◽

Slow Waves ◽

Motor Memory ◽

Temporal Coordination ◽

Phase Amplitude ◽

Related Phase

Targeted memory reactivation (TMR) during post-learning sleep is known to enhance motor memory consolidation but the underlying neurophysiological processes remain unclear. Here, we confirm the beneficial effect of auditory TMR on motor performance. At the neural level, TMR enhanced slow waves (SW) characteristics. Additionally, greater TMR-related phase-amplitude coupling between slow (0.3-2 Hz) and sigma (12-16 Hz) oscillations after the SW peak was related to higher TMR effect on performance. Importantly, sounds that were not associated to learning strengthened SW-sigma coupling at the SW trough and the increase in sigma power nested in the trough of the potential evoked by these unassociated sounds was related to the TMR benefit. Altogether, our data suggest that, depending on their precise temporal coordination during post learning sleep, slow and sigma oscillations play a crucial role in either memory reinstatement or protection against irrelevant information; two processes that critically contribute to motor memory consolidation.

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0104 The Effect of Time, Sleep, and Wake on Motor Memory Consolidation: A Partial Replication of Walker, Et Al. (2002)

SLEEP ◽

10.1093/sleep/zsaa056.102 ◽

2020 ◽

Vol 43 (Supplement_1) ◽

pp. A41-A42

Author(s):

M Tucker ◽

I Wani

Keyword(s):

Memory Consolidation ◽

Memory Task ◽

Skill Learning ◽

Motor Memory ◽

Partial Replication ◽

Motor Sequence ◽

Training Performance ◽

Digit Sequence ◽

Larger Sample ◽

Typing Task

Abstract Introduction Findings from Walker, et al (2002) ‘Practice with Sleep Makes Perfect: Sleep-Dependent Motor Skill Learning’ demonstrate that performance on a widely used motor memory task (motor sequence task (MST)) benefits from a 12hr period of sleep (and not wake) even if the sleep period does not occur for approximately 12hrs after task acquisition, suggesting that sleep is crucial for motor memory consolidation. Using a larger sample, we attempted to replicate this finding, which is derived from Groups B & D from Walker et al (2002). Methods Participants (64 medical students: Age 21.2±0.8; N=33 females) were trained on the MST in the morning (10am; N=40) or evening (10pm; N=24) and then returned 12 and 24hrs later to be retested. The MST is a simple typing task that requires participants, at training, to type a 5-digit sequence (e.g., 4-1-3-2-4) as fast and accurately as possible over a series of 12 30-second trials with a 30-second break between each trial. At each retest, participants performed three 30-second trials. Results With 75% of the data collected we have found that when sleep follows training in the evening (first 12hr interval), the number of correctly typed sequences increased by 19.1% (cf. 20.5% in Walker (2002)). After a subsequent day of wake (second 12hr interval) performance increased by an additional 7.3% (cf. 2.0%). However, when a day of wake spanned the first 12hrs following training, performance increased by 14.5% (cf. 3.9%) followed by another 14.5% increase over the subsequent night (cf. 14.4%). Performance differences between sleep and wake participants were nonsignificant over the first 12hrs (p=0.38) and second 12hrs (p=0.49). Conclusion With most of data collection complete, our findings only partially replicate those of Walker et al (2002), and may draw into question the robustness of sleep for the processing motor memory. Support None

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Role of the somatosensory cortex in motor memory consolidation

Journal of Neurophysiology ◽

10.1152/jn.00770.2019 ◽

2020 ◽

Vol 124 (3) ◽

pp. 648-651

Author(s):

Manasi Wali

Keyword(s):

Motor Learning ◽

Somatosensory Cortex ◽

Memory Consolidation ◽

Motor Memory ◽

Implicit Motor Learning ◽

Implicit Motor ◽

Human Motor ◽

Plos Biol

Motor memories become resistant to interference by the process of consolidation, which leads to long-term retention. Studies have shown involvement of the somatosensory cortex in motor learning-related plasticity, but not directly in motor memory consolidation. This Neuro Forum article reviews evidence from a continuous theta-burst transcranial magnetic stimulation (cTBS) study by Kumar and colleagues (Kumar N, Manning TF, Ostry DJ. PLoS Biol 17: e3000469, 2019) that demonstrates the role of somatosensory, rather than motor, cortex in human motor memory consolidation during implicit motor learning.

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Low acetylcholine during early sleep is important for motor memory consolidation

SLEEP ◽

10.1093/sleep/zsz297 ◽

2019 ◽

Vol 43 (6) ◽

Cited By ~ 4

Author(s):

Samsoon Inayat ◽

Qandeel ◽

Mojtaba Nazariahangarkolaee ◽

Surjeet Singh ◽

Bruce L McNaughton ◽

...

Keyword(s):

Skill Acquisition ◽

Slow Wave ◽

Nicotinic Acetylcholine Receptors ◽

Memory Consolidation ◽

Acetylcholinesterase Inhibitor ◽

Sleep Onset ◽

Motor Memory ◽

Sleep Structure ◽

Rotarod Performance ◽

Cholinergic Tone

Abstract The synaptic homeostasis theory of sleep proposes that low neurotransmitter activity in sleep optimizes memory consolidation. We tested this theory by asking whether increasing acetylcholine levels during early sleep would weaken motor memory consolidation. We trained separate groups of adult mice on the rotarod walking task and the single pellet reaching task, and after training, administered physostigmine, an acetylcholinesterase inhibitor, to increase cholinergic tone in subsequent sleep. Post-sleep testing showed that physostigmine impaired motor skill acquisition of both tasks. Home-cage video monitoring and electrophysiology revealed that physostigmine disrupted sleep structure, delayed non-rapid-eye-movement sleep onset, and reduced slow-wave power in the hippocampus and cortex. Additional experiments showed that: (1) the impaired performance associated with physostigmine was not due to its effects on sleep structure, as 1 h of sleep deprivation after training did not impair rotarod performance, (2) a reduction in cholinergic tone by inactivation of cholinergic neurons during early sleep did not affect rotarod performance, and (3) stimulating or blocking muscarinic and nicotinic acetylcholine receptors did not impair rotarod performance. Taken together, the experiments suggest that the increased slow wave activity and inactivation of both muscarinic and nicotinic receptors during early sleep due to reduced acetylcholine contribute to motor memory consolidation.

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