Neurons are characterised by their intricate polarised morphology, crucial for proper CNS function. Achieving and maintaining this morphology is essential, facilitated by microtubules, key constituents of the neuronal cytoskeleton. Microtubule function is modulated by Microtubule Associated Proteins (MAPs), among which microtubule-stabilising MAP6d1 stands out for being the first neuronal protein identified to be directly involved in the formation of microtubule doublets in vitro. Microtubule doublets are highly stable structures specifically crucial for the formation and functioning of cilia. Neuronal primary cilia, also described as the antennae of neurons, are signalling organelles primarily involved in the modulation of signal transduction. With MAP6d1’s molecular characterisation well underway, we are now striving to elucidate its physiological function in the adult brain. Investigating MAP6d1's localisation within neuronal primary cilia and understanding its impact on microtubular structures within these compartments are current objectives. We found that MAP6d1 indeed seems to localise preferentially to microtubule doublets in neuronal hippocampal primary cilia, co-localising with stable microtubules. In addition, when MAP6d1 is overexpressed, neurons display longer cilia, whereas neurons from MAP6d1-KO mice, display shorter primary cilia. Our results highlight a microtubular role of the protein in primary cilia, supporting their structure and thereby function. Finally, to get a bigger picture of MAP6d1’s physiological role, we have been investigating the behavioural phenotype of MAP6d1-KO mice. These mice exhibit a complex phenotype, characterized by reduced locomotion and emotional function deficits, shedding light on the broader behavioural implications of MAP6d1 dysfunction.