Genetic labeling reveals temporal and spatial expression pattern of D2 dopamine receptor in rat forebrain

Brain Struct Funct. 2019 Apr;224(3):1035-1049. doi: 10.1007/s00429-018-01824-2. Epub 2019 Jan 2.

Abstract

The D2 dopamine receptor (Drd2) is implicated in several brain disorders such as schizophrenia, Parkinson's disease, and drug addiction. Drd2 is also the primary target of both antipsychotics and Parkinson's disease medications. Although the expression pattern of Drd2 is relatively well known in mouse brain, the temporal and spatial distribution of Drd2 is lesser clear in rat brain due to the lack of Drd2 reporter rat lines. Here, we used CRISPR/Cas9 techniques to generate two knockin rat lines: Drd2::Cre and Rosa26::loxp-stop-loxp-tdTomato. By crossing these two lines, we produced Drd2 reporter rats expressing the fluorescence protein tdTomato under the control of the endogenous Drd2 promoter. Using fluorescence imaging and unbiased stereology, we revealed the cellular expression pattern of Drd2 in adult and postnatal rat forebrain. Strikingly, the Drd2 expression pattern differs between Drd2 reporter rats and Drd2 reporter mice generated by BAC transgene in prefrontal cortex and hippocampus. These results provide fundamental information needed for the study of Drd2 function in rat forebrain. The Drd2::Cre rats generated here may represent a useful tool to study the function of neuronal populations expressing Drd2.

Keywords: Cerebral cortex; Drd2; Hippocampus; Knockin rats; Olfactory bulb.

MeSH terms

  • Animals
  • Brain / cytology
  • Clustered Regularly Interspaced Short Palindromic Repeats / genetics
  • Gene Expression Regulation / genetics*
  • Glutamate Decarboxylase / metabolism
  • In Vitro Techniques
  • Luminescent Proteins / genetics
  • Luminescent Proteins / metabolism
  • Male
  • Mice, Transgenic
  • Neurons / metabolism*
  • Olfactory Marker Protein / metabolism
  • Parvalbumins / metabolism
  • Phosphopyruvate Hydratase / metabolism
  • Prosencephalon / cytology
  • Prosencephalon / metabolism*
  • Rats
  • Rats, Sprague-Dawley
  • Rats, Transgenic
  • Receptors, Dopamine D2 / genetics
  • Receptors, Dopamine D2 / metabolism*
  • Transduction, Genetic

Substances

  • DRD2 protein, human
  • DRD2 protein, rat
  • Luminescent Proteins
  • Olfactory Marker Protein
  • Omp protein, mouse
  • Parvalbumins
  • Receptors, Dopamine D2
  • Glutamate Decarboxylase
  • glutamate decarboxylase 1
  • Phosphopyruvate Hydratase