Tetrode optic flow track, supporting "Distance-tuned neurons drive specialized path integration calculations in medial entorhinal cortex"

Data presented here is part of the study "Distance-tuned neurons drive specialized path integration calculations in medial entorhinal cortex" (https://doi.org/10.1016/j.celrep.2021.109669). It consists of recordings of MEC neurons in mice while mice are running down a virtual linear track. Recordings were performed with tetrodes. Furthermore, cells were characterized while mice were freely foraging in an open field environment. For more details, see "Principles governing the integration of landmark and self-motion cues in entorhinal cortical codes for navigation" by Campbell et al, (https://doi.org/10.1038/s41593-018-0189-y). Detailed description of data below. Each .mat file corresponds to data from one cell recorded in one session.The titles are structured as follows:____.matFor example,Ariana_0830_opticflow_1_T1C1.matInside each .mat file is a structure called celldata, which has the following fields:unique_id:Unique ID of the cellmouse:Mouse namesession:Session namecell:Tetrode and cluster of the cellsession_type:Session typespeed_cutoff:Speed cutoff used to compute firing rate maps, in cm/strack_length:Length of the track, in cmtrack_start:Location of the start of the track, in cmtrack_end:Location of the end of the track, in cmbinsize:Size of the spatial bin for firing rate maps, in cmnbins:Number of spatial bins in the firing rate mapbinedges:Edges of the spatial bins for the firing rate maps, in cmnumblocks:Number of blocksws:Structure with whole session data, explained belowbl:Structure with data split by trial blocks (ignore this for optic flow data)of_data:Structure with statistics computed from open field recordings from the same cell. Cells were matched manually by matching waveforms between open field and VR recordings.The ws ("whole session") structure has the following fields, all computed from VR data:posx:Position of the mouse on the VR track in each time binpost:Time of each time bin, in secondslickx:Lick locationslickt:Lick time stampstrialt:Start time of each trial, in secondstrial:Current trial of each time bintrialtype:Type of each trialtrialgainvalues:VR gain of each trialrecording_length:Recording length in secondsdt:Length of each VR frame, in secondstrialblock:Trialblock number of each time binblocktype:Type of each trial blockblockgain:VR gain of each trial blocktrialsperblock:Number of trials per blockgain:VR gain of each time binvrspeed:VR speed at each time bin (in VR cm/sec)realspeed:Real speed at each time bin (VR speed/gain) (in cm/sec)meanspeed:Mean real speed in the session (cm/sec)posx_filt:Same as posx, but filtered to only include time bins above the speed thresholdpost_filt:Same as post, but filtered to only include time bins above the speed thresholdtrial_filt:Same as trial, but filtered to only include time bins above the speed thresholdtrialblock_filt:Same as trialblock, but filtered to only include time bins above the speed thresholdgain_filt:Same as gain, but filtered to only include time bins above the speed thresholddt_filt:Same as dt, but filtered to only include time bins above the speed thresholdspike_t:Spike timesspike_idx:Time bin index for each spikespike_t_filt:Spike times, filtered to only include spikes when speed was above the speed thresholdspike_idx_filt:Time bin index for each spike, filtered to only include spikes when speed was above the speed thresholdThe bl ("block") structure is analogous to the ws structure but split by trial blocks, e.g. with different VR gain. This is irrelevant for optic flow data.The of_data structure has the following fields, all computed from matched open field data (see Methods of Campbell et al. 2018 for description of how they were computed):grid_score:Grid scoreborder_score:Border scorehd_score:Head direction scorespeed_score:Speed scoremean_rate:Mean firing ratestability:Spatial stabilitycoherence:Spatial coherencecoverage:Percentage of open field box covered (percent of bins)box_size:Length of the edge of the square open field box, in cm

本数据集源自研究论文《距离调谐神经元驱动内侧内嗅皮层（medial entorhinal cortex, MEC）的专业化路径积分计算》（https://doi.org/10.1016/j.celrep.2021.109669）。数据集包含小鼠在虚拟线性轨道奔跑时的内侧内嗅皮层神经元记录，记录采用四极电极（tetrode）完成。此外，还对小鼠在开放场环境中自由觅食时的神经元特性进行了表征。更多细节可参考Campbell等人发表的《导航内嗅皮层编码中地标与自运动线索整合的原则》（https://doi.org/10.1038/s41593-018-0189-y）。下文为数据集详细说明。

每个.mat文件对应一次会话中单个记录细胞的数据。文件名格式为：____.mat，例如：Ariana_0830_opticflow_1_T1C1.mat。

每个.mat文件中包含一个名为celldata的结构体，其字段如下：
- unique_id：细胞唯一标识符
- mouse：小鼠名称
- session：会话名称
- cell：细胞对应的四极电极与聚类结果
- session_type：会话类型
- speed_cutoff：用于计算放电率图的速度阈值，单位为cm/s
- track_length：轨道长度，单位为cm
- track_start：轨道起点位置，单位为cm
- track_end：轨道终点位置，单位为cm
- binsize：放电率图的空间分箱尺寸，单位为cm
- nbins：放电率图的空间分箱总数
- binedges：放电率图的空间分箱边界，单位为cm
- numblocks：区块总数
- ws：包含全会话数据的结构体，详见下文
- bl：按试区块拆分的数据结构体（光学流数据可忽略该字段）
- of_data：源自同一细胞开放场记录的统计数据结构体。细胞通过匹配开放场与虚拟现实（Virtual Reality, VR）记录的波形完成手动匹配。

其中ws（全会话）结构体的所有字段均源自VR数据，具体包括：
- posx：每个时间分箱中小鼠在VR轨道上的位置
- post：每个时间分箱的时刻，单位为秒
- lickx：舔舐位置
- lict：舔舐时间戳
- trialt：每个试次的起始时刻，单位为秒
- trial：每个时间分箱对应的当前试次编号
- trialtype：每个试次的类型
- trialgainvalues：每个试次的VR增益值
- recording_length：记录总时长，单位为秒
- dt：每个VR帧的时长，单位为秒
- trialblock：每个时间分箱对应的试区块编号
- blocktype：每个试区块的类型
- blockgain：每个试区块的VR增益值
- trialsperblock：每个试区块包含的试次数量
- gain：每个时间分箱对应的VR增益值
- vrspeed：每个时间分箱的VR速度（单位为VR cm/sec）
- realspeed：每个时间分箱的实际速度（VR速度/增益），单位为cm/sec
- meanspeed：会话内的平均实际速度，单位为cm/sec
- posx_filt：与posx一致，但仅保留速度高于阈值的时间分箱数据
- post_filt：与post一致，但仅保留速度高于阈值的时间分箱数据
- trial_filt：与trial一致，但仅保留速度高于阈值的时间分箱数据
- trialblock_filt：与trialblock一致，但仅保留速度高于阈值的时间分箱数据
- gain_filt：与gain一致，但仅保留速度高于阈值的时间分箱数据
- dt_filt：与dt一致，但仅保留速度高于阈值的时间分箱数据
- spike_t：尖峰（spike）时间
- spike_idx：每个尖峰对应的时间分箱索引
- spike_t_filt：仅保留速度高于阈值时段的尖峰时间
- spike_idx_filt：仅保留速度高于阈值时段的尖峰对应的时间分箱索引

bl（区块）结构体与ws结构体结构类似，但按试区块拆分（例如配置不同VR增益的区块），对光学流数据无参考价值。

of_data结构体的所有字段均源自匹配后的开放场数据（其计算方法详见Campbell等人2018年论文的方法部分），具体包括：
- grid_score：网格评分
- border_score：边界评分
- hd_score：头部方向评分
- speed_score：速度评分
- mean_rate：平均放电率
- stability：空间稳定性
- coherence：空间相干性
- coverage：开放场箱体的覆盖百分比（按分箱占比计算）
- box_size：方形开放场箱体的边长，单位为cm