The Roles of Histamine Receptor 1 (hrh1) in Neurotransmitter System Regulation, Behavior, and Neurogenesis in Zebrafish

• Published in: Molecular neurobiology Vol. 60; no. 11; pp. 6660 - 6675
• Main Authors: Yao, Yuxiao, Baronio, Diego, Chen, Yu-Chia, Jin, Congyu, Panula, Pertti
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-11-2023; Springer Nature B.V
• Subjects: Acetyltransferase; Adults; Autism; Biomedical and Life Sciences; Biomedicine; Cell Biology; Choline O-acetyltransferase; CRISPR; Danio rerio; Dopamine receptors; Down-regulation; Histamine; Histamine receptors; Homeobox; Hybridization; Immunocytochemistry; Islet-1 protein; Locomotion; Lymphocytes T; Mental disorders; Neurobiology; Neurodevelopmental disorders; Neurogenesis; Neurology; Neurosciences; Neurotransmitters; Orexins; Schizophrenia; Startle response; Thigmotaxis; Tyrosine 3-monooxygenase; Zebrafish; Tyrosine hydroxylase; Anxiety; Dopamine; Hypocretin; Habenula
• ISSN: 0893-7648; 1559-1182
• DOI: 10.1007/s12035-023-03447-z

  
Histamine receptors mediate important physiological processes and take part in the pathophysiology of different brain disorders. Histamine receptor 1 (HRH1) is involved in the development of neurotransmitter systems, and its role in neurogenesis has been proposed. Altered HRH1 binding and expression have been detected in the brains of patients with schizophrenia, depression, and autism. Our goal was to assess the role of hrh1 in zebrafish development and neurotransmitter system regulation through the characterization of
hrh1
−/−
fish generated by the CRISPR/Cas9 system. Quantitative PCR, in situ hybridization, and immunocytochemistry were used to study neurotransmitter systems and genes essential for brain development. Additionally, we wanted to reveal the role of this histamine receptor in larval and adult fish behavior using several quantitative behavioral methods including locomotion, thigmotaxis, dark flash and startle response, novel tank diving, and shoaling behavior.
Hrh1
−/−
larvae displayed normal behavior in comparison with
hrh1
+/+
siblings. Interestingly, a transient abnormal expression of important neurodevelopmental markers was evident in these larvae, as well as a reduction in the number of tyrosine hydroxylase 1 (Th1)–positive cells,
th1
mRNA, and
hypocretin
(
hcrt
)-positive cells. These abnormalities were not detected in adulthood. In summary, we verified that zebrafish lacking
hrh1
present deficits in the dopaminergic and hypocretin systems during early development, but those are compensated by the time fish reach adulthood. However, impaired sociability and anxious-like behavior, along with downregulation of
choline O-acetyltransferase a
and
LIM homeodomain transcription factor Islet1
, were displayed by adult fish.