There is another database which is very user friendly to find your target transcript in different tissues, including human and other species. https://www.ebi.ac.uk/gxa/home
Activity dependent gene expression significant for establishing proper neuronal connectivity in the brain has received lot of attention. Activity could be short term or long term and the consequences different.
Since you are interested particularly in the hippocampus, I recommend you read the brilliant work of Nelson Spruston and his colleagues at Janelia Research Campus. Please see
Hipposeq: a comprehensive RNA-seqdatabase of gene expression inhippocampal principal neurons eLife 2016 and his other papers in Neuron.
In addition, you will enjoy reading,
Genome-Wide Profiling of the Activity-Dependent
Hippocampal Transcriptome
Guido Hermey and colleagues in PLOS One October 2013 .