Rapid visual stimulation induces N-methyl-D-aspartate receptor-dependent sensory long-term potentiation in the rat cortex

Abstract

Previously we have demonstrated that rapidly presented sensory stimulation (visual or auditory) can induce long-lasting increases in sensory evoked potentials recorded from the human cortex. Long-term potentiation was suggested as the underlying mechanism of these increases. In the present experiment, we applied the same visual paradigm to anesthetized rats to investigate the properties and mechanisms of this effect. Our results indicated that visual evoked responses were significantly enhanced for at least 1 h and, when followed, up to 5 h after the presentation of a 'photic tetanus.' Furthermore, the potentiation was N-methyl-D-aspartate receptor-dependent and cortically generated. This type of sensory long-term potentiation may underlie perceptual learning, and serves as a model system for investigating sensory-evoked plasticity.

Augmenting NMDA receptor signaling boosts experience-dependent neuroplasticity in the adult human brain

“…This is consistent with prior findings that DCS augmented increases in motor cortex excitability following anodal transcranial direct-current stimulation in humans (37) and augmented LTP in rat hippocampus following high-frequency electrical stimulation (38,39). Our finding is also consistent with preclinical studies demonstrating that potentiation of the VEP following HFvS is NMDAR dependent (8).…”

“…It persists into adulthood, is frequently NMDAR dependent, and has been observed at subcortical and sensory cortex synapses (1-6). Although classical LTP studies used high-frequency electrical stimulation to induce LTP, HFvS also induces lasting potentiation of neural responses (8)(9)(10)(11)(12)(13)(14), and potentiated neural responses following HFvS show cardinal features of synaptic LTP (7,8). In the current study, participants who received DCS showed greater potentiation of the VEP following HFvS compared with participants who received placebo.…”

“…Although a lack of noninvasive methods has traditionally limited our ability to investigate LTP in humans, recent research indicates that protocols using high-frequency, repetitive presentation of visual or auditory stimuli provide a naturalistic method for inducing LTP in humans and animals. Studies in rodents demonstrated that changes in neural responses following repetitive sensory stimulation show the cardinal features of synaptic LTP, including persistence (>1 h), input specificity, and NMDAR dependency (7,8). Furthermore, these LTP-like changes can be measured noninvasively as changes in sensory evoked potentials, which are stimulus-synchronized electroencephalograph (EEG) signals that result from postsynaptic potentials in populations of sensory neurons.…”

Long-Term Plasticity in Mouse Sensorimotor Circuits after Rhythmic Whisker Stimulation

“…The increased amplitude of the early latency current sink in layer IV of the barrel cortex also suggests that at least part of the potentiation in this system could be located at the thalamocortical synapse or at subcortical synapses. It should be noted here that, because SEP waveforms, particularly laterlatency components, are generated by the combined activity of several neuronal populations (Di et al, 1990;Jellema et al, 2004), waveform plasticity may reflect synaptic plasticity as well as plasticity occurring through other mechanisms, such as changes in neuronal excitability or in the activity of inhibitory interneurons ( Clapp et al, 2006). Interestingly, earlier studies showed that rhythmically patterned bursts of electrical stimulation in thalamic sensory relay nuclei, with frequencies of 5-7 Hz, could induce long-lasting potentiation of cortical responses to natural peripheral or single-pulse thalamic stimulation in the adult rat (Lee and Ebner, 1992;Heynen and Bear, 2001).…”

“…It might also be that this activity facilitates the generation of long-term adaptive changes in cortical function that underlie perception (Gilbert et al, 2001). Recent evidence suggests that periods of rhythmical visual or auditory stimulation can induce properties of synaptic plasticity such as long-term potentiation of cortical responses evoked by sensory inputs (Clapp et al, , 2006Teyler et al, 2005). Whether similar mechanisms could be related to whisking activity and whether such changes could be behaviorally relevant is not known.…”