The expression of tyrosine hydroxylase and DARPP‐32 in the house crow (Corvus splendens) brain

Abstract

Birds of the family Corvidae which includes diverse species such as crows, rooks, ravens, magpies, jays, and jackdaws are known for their amazing abilities at problem‐solving. Since the catecholaminergic system, especially the neurotransmitter dopamine, plays a role in cognition, we decided to study the distribution of tyrosine hydroxylase (TH), the rate‐limiting enzyme in the synthesis of catecholamines in the brain of house crows (Corvus splendens). We also studied the expression of DARPP‐32 (dopamine and cAMP‐regulated phosphoprotein), which is expressed in dopaminoceptive neurons. Our results demonstrated that as in other avian species, the expression of both TH and DARPP‐32 was highest in the house crow striatum. The caudolateral nidopallium (NCL, the avian analogue of the mammalian prefrontal cortex) could be differentiated from the surrounding pallial regions based on a larger number of TH‐positive “baskets” of fibers around neurons in this region and greater intensity of DARPP‐32 staining in the neuropil in this region. House crows also possessed distinct nuclei in their brains which corresponded to song control regions in other songbirds. Whereas immunoreactivity for TH was higher in the vocal control region Area X compared to the surrounding MSt (medial striatum) in house crows, staining in RA and HVC was not as prominent. Furthermore, the arcopallial song control regions RA (nucleus robustus arcopallialis) and AId (intermediate arcopallium) were strikingly negative for DARPP‐32 staining, in contrast to the surrounding arcopallium. Patterns of immunoreactivity for TH and DARPP‐32 in “limbic” areas such as the hippocampus, septum, and extended amygdala have also been described.

A comparative analysis of the dopaminergic innervation of the executive caudal nidopallium in pigeon, chicken, zebra finch, and carrion crow

“…The current designated NCLd corresponds to their mNCL, and what we termed NCLv relates to their lNCL. Sen et al () do not explicitly describe NCLm, but the area can be distinguished from their stained slices (compare Figure in Sen et al, ). We propose this change in nomenclature for two reasons.…”

Altering Opioid Neuromodulation in the Songbird Basal Ganglia Modulates Vocalizations

“…Immunoblotting was used to validate the specificity of the anti-μ-OR antibody (1:5000; Abcam, ab10275, polyclonal; made in rabbit, which detects a band of 49–65 kDa) and peroxidase-labeled secondary antibody (anti-rabbit; 1:6000, Vector Laboratories, PI-1000) used to detect μ-ORs in zebra finches (Figure 1C; cf. Sen et al, 2019). The anti-μ-OR antibody (ab10275) was raised against a sequence of 15 amino acids on the C-terminal (384 to 398) of OPRM-1; NX_P35372, which is a synthetic rat μ-OR peptide.…”

Blocking Opioid Receptors in a Songbird Cortical Region Modulates the Acoustic Features and Levels of Female-Directed Singing

“…The antibody used to detect μ-ORs (Abcam, ab10275, made in rabbit) has been validated using western blots in an earlier publication from our lab ( Kumar et al, 2019 ). To validate the specificity of the anti-GAD67 antibody (Abcam, ab26116, raised in mouse), a western blot was performed by the same method using whole brain protein lysate from adult male zebra finches separated by SDS-PAGE (11%; Kumar et al, 2019 ; Sen et al, 2019 ). The anti-GAD67 antibody was raised against a synthetic peptide corresponding to amino acids 87–106 of Human GAD67.…”