Adaptation Shifts Preferred Orientation of Tuning Curve in the Mouse Visual Cortex

Abstract

In frontalized mammals it has been demonstrated that adaptation produces shift of the peak of the orientation tuning curve of neuron following frequent or lengthier presentation of a non-preferred stimulus. Depending on the duration of adaptation the shift is attractive (toward the adapter) or repulsive (away from the adapter). Mouse exhibits a salt-and-pepper cortical organization of orientation maps, hence this species may respond differently to adaptation. To examine this question, we determined the effect of twelve minutes of adaptation to one particular orientation on neuronal orientation tuning curves in V1 of anesthetized mice. Multi-unit activity of neurons in V1 was recorded in a conventional fashion. Cells were stimulated with sine-wave drifting gratings whose orientation tilted in steps. Results revealed that similarly to cats and monkeys, majority of cells shifted their optimal orientation in the direction of the adapter while a small proportion exhibited a repulsive shift. Moreover, initially untuned cells showing poor tuning curves reacted to adaptation by displaying sharp orientation selectivity. It seems that modification of the cellular property following adaptation is a general phenomenon observed in all mammals in spite of the different organization pattern of the visual cortex. This study is of pertinence to comprehend the mechanistic pathways of brain plasticity.

Comparative effects of adaptation on layers II–III and V–VI neurons in cat V1

“…A part of the remaining population refracted the adapter and did not show any significant shift (< 5°) in orientation tuning (Bachatene et al ., , ; Jeyabalaratnam et al ., ). The corresponding proportion of repulsive shifts for both layers was found to be comparable (06 neurons in supra‐ and 07 in infragranular layers).…”

“…A proportion analysis was not performed on these latter datasets as we were primarily interested in comparing only attractive and repulsive behaviors across layers. Such novel selectivity has been reported previously in mice (Jeyabalaratnam et al ., ). It is to be underlined that neurons with an orientation selectivity index (OSI) < 0.5 were classified as untuned (Bharmauria et al ., , ).…”

Comprehensive chronic laminar single-unit, multi-unit, and local field potential recording performance with planar single shank electrode arrays

“…Some SU demonstrated strong tuning curves, but others did not. However, it has been well characterized that in primary visual cortex, many neurons do not exhibit strong tuning preferences, such as luminance, adaptation, position, and contrast cells(Antolik and Bednar, 2011; Dai and Wang, 2012; Gavornik and Bear, 2014; Harding and Fylan, 1999; Jeyabalaratnam et al, 2013; Niell and Stryker, 2008; Vetter et al, 2014). Therefore, this work focuses on longitudinal characterization of broad evoked firing rate changes.…”

“…Therefore, this work focuses on longitudinal characterization of broad evoked firing rate changes. Furthermore, without a tetrode configuration or intracellular electrodes, a single recording site cannot discriminate between two SU with similar waveforms but distinct tuning curves, which is further complicated by the salt-and-pepper organization of the rodent cortex(Jeyabalaratnam et al, 2013). In addition, previous studies have demonstrated that the awake cortex is dominated by inhibition(Haider et al, 2013).…”

“…While a fixed grating size, temporal drift frequency and grating spacing were employed in this study, adjusting these parameters could evoke responses in additional neurons that were unresponsive to our stimulus due to their spatial and temporal frequency tuning, or to surround suppression to the large grating. Nonetheless, most neurons in visual cortex are sensitive to stimuli with a broad range of spatial and temporal frequencies and sizes(De Valois et al, 1982; Jeyabalaratnam et al, 2013; Land et al, 2013b), so we expect that our choice of stimulus type did not greatly impact the size of the evoked population. It has also been well characterized that not all units in the visual cortex exhibit strong tuning curves due to lateral inhibition or because they preferentially encode luminance, adaptation, or contrast changes (Antolik and Bednar, 2011; Brodie et al, 1978; Dai and Wang, 2012; Foster et al, 1985; Harding and Fylan, 1999; Jeyabalaratnam et al, 2013; Kuhlman et al, 2011; Olsen et al, 2012).…”