Browsing by Author "Gur, Ezgi"

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Mice Extrapolate Temporal Information Based on Previously Learned Spatiotemporal Mappings: An Asymmetrical Case
(Springer, 2026) Gur, Ezgi; Duyan, Yalcin A.; Toptas, Pinar; Balci, Fuat
One of the computational affordances of isomorphic magnitude representations is the extrapolation of temporal information based on previously experienced spatiotemporal pairings. We initially trained mice on the association of two intervals (10 s and 30 s) with two hoppers (H2 and H4, counterbalanced) in a five-choice nose-poke box with the following setup. One of the three novel hoppers (H1) neighbored H2 only, the other novel hopper (H5) neighbored H4 only, and the third novel hopper (H3) neighbored H2 and H4 (H1Novel -> H2Trained -> H3Novel -> H4Trained -> H5Novel). During test trials, one of the five hoppers was illuminated. We estimated the trial time at which the anticipatory response rate was maximal (peak time) separately for each hopper. Mice extrapolated temporal information only in a forward fashion; the peak time for H5 was longer than that for H4. Mice did not extrapolate temporal information backward; the timed response curves in H1 and H3 were closely similar to those in H2. Thus, our findings suggest that mice can extrapolate temporal information, but also indicate that the computations underlying this process are directionally constrained. We discuss the possible reasons behind asymmetrical extrapolation.
Midbrain Dopamine Warps Subjective Time via Threshold Setting But Not Clock Speed
(Soc Neuroscience, 2026) Erdagi, Alihan; Gur, Ezgi; Balci, Fuat
Interval timing is an evolutionarily well-preserved function that presents similar behavioral signatures across different species. However, the neural basis of interval timing remains an open question. For instance, although dopamine has been implicated as a vital component of the internal clock, its precise role is debated due to equivocal findings from various methodologies and their interpretations. We tested this question by optogenetically exciting versus inhibiting tyrosine hydroxylase-positive (TH+) neurons of the substantia nigra pars compacta while male mice produced at least a 3-s-long interval by depressing a lever for reward. Excitation of TH+ neurons shifted their timing behavior to the right, while inhibition led to a shift to the left. Our drift-diffusion timing model-based analysis of the behavioral data clearly showed that TH+ neuron excitation and inhibition heightened and lowered the timing threshold, respectively, without affecting the rate of temporal integration (i.e., clock speed). Our work attributes a clear mechanistic role (i.e., threshold setting) to nigrostriatal dopaminergic function as part of the internal clock.