Acupuncture has been a foundational clinical therapy in East Asian countries, such as Korea and China for over 2000 years [1]. In Western countries, acupuncture is increasingly recognized as a complementary medical practice with a scientific foundation utilized for the treatment of various conditions, such as pain, nausea, and cardiovascular diseases [[2], [3], [4]]. Recently, acupuncture has gained attention as a promising intervention, particularly for patients with mental or psychiatric disorders, such as anxiety and depression [5,6]. Acupuncture treatment is occasionally observed to have advantages over medication owing to its immediate therapeutic effects and minimal side effects in certain conditions [7].

Although extensive research has explored the various pathways underlying the effects of acupuncture, a comprehensive understanding of the mechanisms of acupuncture remains limited [8]. Over the past few years, functional magnetic resonance imaging (fMRI) studies have increasingly shown that acupoints specifically affect the regions of the brain associated with pain, emotion, and motor function [9]. A neuroanatomical model has been proposed to strengthen the physiological and theoretical effects of the meridians and acupoints [10]. One group demonstrated how electroacupuncture at ST36 drives the vagal–adrenal axis using a neuroanatomical approach [11]. In addition, acupuncture modulates the autonomic nervous system by influencing central autonomic regulation through pathways involving neurotransmitters and brain regions, such as the hypothalamus and brainstem [12].

In particular, PC8 (Laogong), located between the 2nd and 3rd metacarpal bones on the palm, is one of the most well-known acupoints closely related to the nervous system and belongs to the meridians of the pericardium according to traditional Korean medicine [13,14]. It is often used to treat heart and mental illnesses, as well as emotional and cognitive disorders [14]. Additionally, electrical acupuncture treatment to two pairs of PC8 and other acupoints reduced the urge to smoke in cigarette-addicted individuals, demonstrating its effects on both neurological pathways and behavioral disorders [15]. A neuroanatomical study demonstrated that the PC8 region is connected to the dorsal horn of the spinal cord and the cuneate nucleus of the medulla oblongata within the C6 to T1 spinal segments [16]. These findings indicate that PC8 has a direct influence on the central nervous system [15,16].

Despite the importance of the PC8 acupoint in terms of clinical applications, the anatomical features for the PC8 acupoint are not well-studied at the neuroanatomical level yet. Thus, we sought to clarify the neuroanatomical characteristics of the PC8 acupoint in relation to the surrounding muscles and tendons.