DOI: 10.5061/dryad.fxpnvx11h
title: Data from: Effects of maternal age and environmental enrichment on learning ability and brain size

description: It is well known that maternal age at reproduction affects offspring
 lifespan and some other fitness-related traits, but it remains
 understudied whether maternal senescence affects how offspring respond to
 their environments. Early environment often plays a significant role in
 the development of an animal’s behavioral phenotype. For example, complex
 environments can promote changes in cognitive ability and brain morphology
 in young animals. Here, we study whether and how maternal effect
 senescence influences offspring plasticity in cognition, group behavior,
 and brain morphology in response to environmental complexity. For this,
 juvenile three-spined sticklebacks from young and old mothers (i.e. 1-year
 and 2-years-old) were exposed to different levels of environmental
 enrichment and complexity (i.e. none, simple and complex), and their
 behavior, cognitive ability, and brain size were measured. Exposing fish
 to enriched conditions improved individual learning ability assessed by a
 repeated detour-reaching task, increased the size of the whole brain, and
 decreased aggressive interactions in the shoal. Maternal age did not
 influence the inhibitory control, learning ability, and group behavioral
 responses of offspring to the experimental environmental change. However,
 maternal age affected how some brain regions of offspring changed in
 response to environmental complexity. In offspring from old mothers, those
 exposed to the complex environment had larger telencephalons and
 cerebellums than those who experienced simpler environments. Our results
 suggest that maternal effect senescence may influence how offspring invest
 in brain functions related to cognition in response to environmental
 complexity.
description: # Effects of maternal age and environmental enrichment on learning ability
 and brain size
 [https://doi.org/10.5061/dryad.fxpnvx11h](https://doi.org/10.5061/dryad.fxpnvx11h) The dataset provided includes all data necessary to reproduce the analyses and results contained in the article. ## Description of the data and file structure The Excel consists of 7 sheets named as 'ind', 'cog', 'cog2', 'repgrowth', 'aggression', 'activ' and 'expl' for reproducing the analyses at the individual level, analyses of repeated measures of detour-reaching tasks scores before and after treatment, body size and mass, and data for behavioural assessment of agression, activity and exploration respectively. Here is the description of the abreviations used: **'ind'** id: individual identity. tank: tank identity in which the group of fish was maintained. agedam: age of mother ( o = old and y = young). tag: colour of the elastomer tag. family: family identity. dam: identity of the mother. sire: father identity. treat: complexity of environmental enrichment treatment (n = none; c = complex and s = simple). sex: male or female. age1: age at detour reaching task before the treatment, in days. age2: age at detour reaching task after the treatment, in days. wt1: weight in g before the treatment. sl1: length in mm before the treatment. wt2: weight in g after the treatment. sl2: length in mm after the treatment. score11: time to solve the first detour reaching task before the treatment (in minutes). score12: time to solve the second detour reaching task before the treatment (in minutes). score13: time to solve the third detour reaching task before the treatment (in minutes). score21: time to solve the first detour reaching task after the treatment (in minutes). score22: time to solve the second detour reaching task after the treatment (in minutes). score23: time to solve the third detour reaching task after the treatment (in minutes). status: 0 = alive or 1 = dead suring the course of the experiment. time: day of death during the study or last observation if the individual was alive at the end of the experiment. startexp: start date of the experiment. date: date of death. n_dead: number of dead fish per group. n_total: total number of fish per group. prop_dea: proportion of dead fish. voltelencephalon: volume of the telencephalon. voloptictectum: volume of the optic tectum. volcerebellum: volume of the cerebellum. volhypothalamus: volume of the hypothalamus. voltotal: total brain volume. **'cog'** time: 1 = first, 2 = second or 3 = third detour reaching task. order: order of testing within the group (1 = first; 2 = second; and 3 = third). score1: time taken to solve the detour reaching task (first, second or third) before the treatment (in minutes). '**cog2'** score2: time taken to solve the detour reaching task (first, second or third) after the treatment (in minutes). **'repgrowth'** age: age in days before and after treatment (when measured and weighed for thew first and second time). time: time at which the weight and length were measured (1 = first or 2 = second). wt: weight in grams. sl: standard length in mm. **'aggression'** apparatus: apparatus (1-4) used to add complexity during the environmental enrichment treatment (one apparatus per treatment week). day: observation day (1 = first and 3 = third day of exposition to each apparatus). ob1: aggressive interactions detected at each observation (1-20) of the scan sampling (ob1 = at minute 1; ob2 = at minute 2; ob3 = at minute 3; ob4 = at minute 4;  ob5 = at minute 5; ob6 = at minute 6; ob7 = at minute 7; ob8 = at minute 8; ob9 = at minute 9; ob10 = at minute 10; ob11 = at minute 11; ob12 = at minute 12; ob13 = at minute 13; ob14 = at minute 14; ob15 = at minute 15; ob16 = at minute 16; ob17 = at minute 17; ob18 = at minute 18; ob19 = at minute 19; ob20 = at minute 20). interac: total number of aggressive interactions over the 20 minute scan sample. obstotal: total number of observations. propinterac: proportion of aggressive interactions. date: date of observation. **'activ'** ob1: number of fish actively swimming at each observation (1-20) of the scan sampling (ob1 = at minute 1; ob2 = at minute 2; ob3 = at minute 3; ob4 = at minute 4;  ob5 = at minute 5; ob6 = at minute 6; ob7 = at minute 7; ob8 = at minute 8; ob9 = at minute 9; ob10 = at minute 10; ob11 = at minute 11; ob12 = at minute 12; ob13 = at minute 13; ob14 = at minute 14; ob15 = at minute 15; ob16 = at minute 16; ob17 = at minute 17; ob18 = at minute 18; ob19 = at minute 19; ob20 = at minute 20). nobsactiv: number of observations where fish were swimming. nmaxactiv: maximum number of fish swimming during the entire scan sampling. propactiv: proportion of observations out of the total where at least one fish was observed swimming. propmaxactiv: proportion of maximum number of fish observed swimming out of the total number of fish. date: date of observation. n_total: total number of fish per group. **'expl'** ob1: number of fish actively exploring at each observation (1-20) of the scan sampling (ob1 = at minute 1; ob2 = at minute 2; ob3 = at minute 3; ob4 = at minute 4;  ob5 = at minute 5; ob6 = at minute 6; ob7 = at minute 7; ob8 = at minute 8; ob9 = at minute 9; ob10 = at minute 10; ob11 = at minute 11; ob12 = at minute 12; ob13 = at minute 13; ob14 = at minute 14; ob15 = at minute 15; ob16 = at minute 16; ob17 = at minute 17; ob18 = at minute 18; ob19 = at minute 19; ob20 = at minute 20). nobsexpl: total number of observations with at least one fish exloring during the entire 20 min scan sampling period. nmaxexpl:  maximum number of fish exploring over the entire scan sampling period. propexpl:  proportion of observations out of the total in which at least one fish was observed exploring. propmaxexpl: proportion of the maximum number of fish observed exploring out of the total number. *Variables that are repeated between sheets are described once. **Empty cells** correspond to individuals who had died during the course of the study. Therefore there are no observations for those individuals for traits assessed after their death.